|
Thread Rules
1. This is not a "do my homework for me" thread. If you have specific questions, ask, but don't post an assignment or homework problem and expect an exact solution.
2. No recruiting for your cockamamie projects (you won't replace facebook with 3 dudes you found on the internet and $20)
3. If you can't articulate why a language is bad, don't start slinging shit about it. Just remember that nothing is worse than making CSS IE6 compatible.
4. Use [code] tags to format code blocks. |
What is wrong with this lines of code
#include <glib.h>
GArray *position1;
GArray *position2;
GArray *velocity1;
GArray *velocity2;
position1 = g_array_new(FALSE, FALSE, sizeof (double));
position2 = g_array_new(FALSE, FALSE, sizeof (double));
velocity1 = g_array_new(FALSE, FALSE, sizeof (GArray));
velocity2 = g_array_new(FALSE, FALSE, sizeof (GArray));
Compiler says something about "int" and "int *", also something about a Constant and that "this declaration has no storage class or type specifier".
|
Germany153 Posts
On August 22 2012 16:22 SiPa wrote:What is wrong with this lines of code
#include <glib.h>
GArray *position1;
GArray *position2;
GArray *velocity1;
GArray *velocity2;
position1 = g_array_new(FALSE, FALSE, sizeof (double));
position2 = g_array_new(FALSE, FALSE, sizeof (double));
velocity1 = g_array_new(FALSE, FALSE, sizeof (GArray));
velocity2 = g_array_new(FALSE, FALSE, sizeof (GArray));
Compiler says something about "int" and "int *", also something about a Constant and that "this declaration has no storage class or type specifier".
I've not coded in a very long time, but is there supposed to be a "space" between the sizeof function and the brackets of that very function?
And i think a clear compiler message, would help alot =)
|
On August 22 2012 16:30 fearpLug wrote:Show nested quote +On August 22 2012 16:22 SiPa wrote:What is wrong with this lines of code
#include <glib.h>
GArray *position1;
GArray *position2;
GArray *velocity1;
GArray *velocity2;
position1 = g_array_new(FALSE, FALSE, sizeof (double));
position2 = g_array_new(FALSE, FALSE, sizeof (double));
velocity1 = g_array_new(FALSE, FALSE, sizeof (GArray));
velocity2 = g_array_new(FALSE, FALSE, sizeof (GArray));
Compiler says something about "int" and "int *", also something about a Constant and that "this declaration has no storage class or type specifier". I've not coded in a very long time, but is there supposed to be a "space" between the sizeof function and the brackets of that very function? And i think a clear compiler message, would help alot =)
Error messages are in german, what i gave you are pretty "clear" translations.
Well, error-codes are:
error C2143 in line 4-7
errors C2040 and 2099 in line 9-12
"IntelliSense: this declaration has no storage class or type specifier" in line 9-12
Also: although i told my compiler (Microsoft VisualStudio 2010 to compile in C, it produces errors even in garray.h
I now believe there's something wrong with my GLib stuff :S
|
Germany153 Posts
|
#include <stdlib.h>
#include <stdio.h>
#include <glib.h>
int main(void)
{
//Random stuff, that works!
int x = 3;
int y = 2;
int z = 0;
int i = 0;
for (i= 0; i<=100000000; ++i)
{
z = x + y;
printf("%d\n", z);
}
//Stuff that doesnt work
GArray *position1;
GArray *position2;
GArray *velocity1;
GArray *velocity2;
position1 = g_array_new(FALSE, FALSE, sizeof(double));
position2 = g_array_new(FALSE, FALSE, sizeof(double));
velocity1 = g_array_new(FALSE, FALSE, sizeof(GArray));
velocity2 = g_array_new(FALSE, FALSE, sizeof(GArray));
return 0;
}
http://imgur.com/L2Umo
I will commence writing in english, so other ppl dont get annoyed; only thing in german will be the errors...
Sooo
I dont see much difference between this and the example-code, exept for me using double and GArray for sizeof().
|
Germany153 Posts
so the problem is, that ur compiler wont accept the declaration of the Garray data type, therefore everything that follows wont work. thats what the compiler said ;D
|
any idea what i can do?
I'm kinda lost here...
|
Germany153 Posts
gimme a sec ill install a compiler and test it my self, 5 mins^^
edit: sorry cant seem to get the compiler working at my company pc, damn security and all 8/
Hm if i had to take a guess, its either a wrong compiler and implemented glib or ur compiler isnt liking glib at( buggy ).
U could test to either do a new document and see if this fixes it, or could try another compiler.
If both dont seem to be the error, well then there not much i can think of, cause ur syntax seems 2 be right.
|
Hmk, i guess i dont really have to use GLib...it wouldve been just so much easier.
Well thx for your time and all ^^
|
Hmm stayed in this thread for 12 hours straight, should maybe Grab some food...
Now to my question: I've spent the Last half year working on a OS written in C for a microcontroller on with a Studio called Avr Studio 4 where for example different types of integers (u_int8) and several Hardware specific small "Extras" were used, how well did that teach me "General" C? I'm a bit curios, which Ressource to Test my skills can you guys recommend? Thanks in advance.
Sorry for Bad spelling my german autocorrect runs crazy on my phone TT.
|
On August 22 2012 16:49 SiPa wrote:... http://imgur.com/L2UmoI will commence writing in english, so other ppl dont get annoyed; only thing in german will be the errors... Sooo I dont see much difference between this and the example-code, exept for me using double and GArray for sizeof().
All variables need to be declared at the top. So you can you do this:
int main(void)
{
//Random stuff, that works!
int x = 3;
int y = 2;
int z = 0;
int i = 0;
GArray *position1;
GArray *position2;
GArray *velocity1;
GArray *velocity2;
for (i= 0; i<=100000000; ++i)
{
z = x + y;
printf("%d\n", z);
}
position1 = g_array_new(FALSE, FALSE, sizeof(double));
position2 = g_array_new(FALSE, FALSE, sizeof(double));
velocity1 = g_array_new(FALSE, FALSE, sizeof(GArray));
velocity2 = g_array_new(FALSE, FALSE, sizeof(GArray));
return 0;
}
or this:
int main(void)
{
//Random stuff, that works!
int x = 3;
int y = 2;
int z = 0;
int i = 0;
GArray *position1 = g_array_new(FALSE, FALSE, sizeof(double));
GArray *position2 = g_array_new(FALSE, FALSE, sizeof(double));
GArray *velocity1 = g_array_new(FALSE, FALSE, sizeof(GArray));
GArray *velocity2 = g_array_new(FALSE, FALSE, sizeof(GArray));
for (i= 0; i<=100000000; ++i)
{
z = x + y;
printf("%d\n", z);
}
return 0;
}
|
On August 22 2012 19:20 Pimpmuckl wrote:
Hmm stayed in this thread for 12 hours straight, should maybe Grab some food...
Now to my question: I've spent the Last half year working on a OS written in C for a microcontroller on with a Studio called Avr Studio 4 where for example different types of integers (u_int8) and several Hardware specific small "Extras" were used, how well did that teach me "General" C? I'm a bit curios, which Ressource to Test my skills can you guys recommend? Thanks in advance.
Sorry for Bad spelling my german autocorrect runs crazy on my phone TT.
I'm not sure I entirely understand your question. Are you worried because standard C doesn't have a "u_int8" type? If so, then don't worry, people define their integer types in sorts of ways and you can always define it yourself if you want to use a certain type-scheme. Like: typedef unsigned char uint_8; If your OS class was as hard as mine was, then I'm sure that all that you learned will make you a much better "general" C programmer. To test your skills, find more shit to program 
|
On August 22 2012 19:20 Pimpmuckl wrote:
Hmm stayed in this thread for 12 hours straight, should maybe Grab some food...
Now to my question: I've spent the Last half year working on a OS written in C for a microcontroller on with a Studio called Avr Studio 4 where for example different types of integers (u_int8) and several Hardware specific small "Extras" were used, how well did that teach me "General" C? I'm a bit curios, which Ressource to Test my skills can you guys recommend? Thanks in advance.
Sorry for Bad spelling my german autocorrect runs crazy on my phone TT.
I dabbled in microprocessor programming and while it teaches you a lot about memory management and such, it also teaches you a horrible style that is very focussed on keeping the program and memory footprint small. That is nice in normal C applications but in many cases completely destroys the maintainability of the software.
In normal programming, wasting memory and processing time is in 99.9% of the cases better than writing ugly but efficient code (as long as it's not "leaking memory").
As for testing your skills, i liked http://projecteuler.net/ a lot, though it is not directly for programming and very math focussed but you can improve your problem solving and logic skills through it.
|
EDIT: Nevermind changing repaint to paint(getGraphics()); solved my problem
|
So, I am just starting college again (majoring in CS specialized in programming) and I really hate my job at the moment. I was wondering if anybody knew what kind of programming language could net decent part time pay or can nab random jobs for a couple hundred here and there off craigslist or something. My mom was telling me that drupal or wordpress would be a good start and is in high demand, but I wanted to check around and see what other people think.
|
Hey you programming pros, i need some help as I have problems with the sudoku backtracking algorithm.
I am pretty sure my other programm parts are fine and it is just the actual algorithm.
Here is the code:
void solve(int r=0, int c=0, bool forward=1) //solving algorithm
{
cout << "funktionseinstieg"<<endl; //debugging information
if(vordefiniertefelderarray[r][c]==0) //see if field is predefined
{
for(int i=0; i<9; i++)
{
cout <<"schleifenanfang"<<endl; //debugging information
sudfeld[r][c]+=1; //increase value until it fits
feldausgeben(sudfeld); //debugging information
if(!check(r,c,sudfeld[r][c])) //see if value fits
{
cout << "check war negativ"<<endl;
if(c==8&&r==8) //solving should end here if it's already the last field
{
feldausgeben(sudfeld);
return;
}
i=9; //not really sure if i need this, probably not
if(c<8) //go to next field after right value was found
solve(r,c+1,true);
else solve(r+1,0,true);
}
else //go to previous field if right value coul not be found and set current value to 0 again
{
if(sudfeld[r][c]==9)
{
sudfeld[r][c]=0;
if(c>0)
solve(r,c-1,false);
else solve(r-1,8,false);
}
}
}
}
else //if field was predefined
{
cout<<"feldschonbelegt"; //debugging information
if(c==8&&r==8) ////solving should end here if it's already the last field
{
feldausgeben(sudfeld); //debugging information
return;
}
if(forward) //go to next field if forward value is true, previous field if not
{
if(c<8)
solve(r,c+1,true);
else solve(r+1,0,true);
}
else
{
if(c>0)
solve(r,c-1,false);
else solve(r-1,8,false);
}
}
}
I hope you don't mind to much that some function's names are in german. I commented extensively in english to make up for that.
The problems appearantly start when the programm needs to go to a previous field. Possibly involving predefined values.
Thanks in advance.
If somebody would like to see the whole code:
+ Show Spoiler +
#include <iostream>
using namespace std;
int sudfeld[9][9];
int vordefiniertefelderarray[9][9];
void feldausgeben(int feld[9][9])
{
for(int i=0;i<9;i++)
{
for(int j=0;j<9;j++)
{
cout<<feld[i][j];
if(j==8)
cout << endl;
if(i==8&&j==8)
cout << endl;
}
}
}
bool box(int row, int column, int wert)
{
sudfeld[row][column]=10;
int r= (row/3)*3;
int c= (column/3)*3;
for(int i=r;i<(r+3);i++)
{
for(int j=c;j<(c+3);j++)
{
if(sudfeld[i][j]==wert)
{
cout<<"inboxgefunden";
sudfeld[row][column]=wert;
return true;
}
}
}
sudfeld[row][column]=wert;
return false;
}
bool zeile(int row,int column, int wert)
{
sudfeld[row][column]=10;
for(int i=0;(i<9);i++)
{
if(sudfeld[row][i]==wert)
{
cout<<"inzeilegefunden";
sudfeld[row][column]=wert;
return true;
}
}
sudfeld[row][column]=wert;
return false;
}
bool spalte(int row, int column, int wert)
{
sudfeld[row][column]=10;
for(int i=0;i<9;i++)
{
if(sudfeld[i][column]==wert)
{
cout<<"inspaltegefunden"<<endl;
sudfeld[row][column]=wert;
return true;
}
}
sudfeld[row][column]=wert;
return false;
}
bool check(int row, int column, int wert)
{
if(box(row,column,wert)||zeile(row,column,wert)||spalte(row,column,wert))
{
cout<<"iwogefunden"<<endl;
return true;
}
else
return false;
}
void solve(int r=0, int c=0, bool forward=1) //solving algorithm
{
cout << "funktionseinstieg"<<endl; //debugging information
if(vordefiniertefelderarray[r][c]==0) //see if field is predefined
{
for(int i=0; i<9; i++)
{
cout <<"schleifenanfang"<<endl; //debugging information
sudfeld[r][c]+=1; //increase value until it fits
feldausgeben(sudfeld); //debugging information
if(!check(r,c,sudfeld[r][c])) //see if value fits
{
cout << "check war negativ"<<endl;
if(c==8&&r==8) //solving should end here if it's already the last field
{
feldausgeben(sudfeld);
return;
}
i=9; //not really sure if i need this, probably not
if(c<8) //go to next field after right value was found
solve(r,c+1,true);
else solve(r+1,0,true);
}
else //go to previous field if right value coul not be found and set current value to 0 again
{
if(sudfeld[r][c]==9)
{
sudfeld[r][c]=0;
if(c>0)
solve(r,c-1,false);
else solve(r-1,8,false);
}
}
}
}
else //if field was predefined
{
cout<<"feldschonbelegt"; //debugging information
if(c==8&&r==8) ////solving should end here if it's already the last field
{
feldausgeben(sudfeld); //debugging information
return;
}
if(forward) //go to next field if forward value is true, previous field if not
{
if(c<8)
solve(r,c+1,true);
else solve(r+1,0,true);
}
else
{
if(c>0)
solve(r,c-1,false);
else solve(r-1,8,false);
}
}
}
int main()
{
for(int i=0;i<9;i++)
{
for(int j=0;j<9;j++)
{
sudfeld[i][j]=0;
}
}
for(int i=0;i<9;i++)
{
for(int j=0;j<9;j++)
{
vordefiniertefelderarray[i][j]=0;
}
}
vordefiniertefelderarray[0][5]=2;
vordefiniertefelderarray[1][6]=2;
vordefiniertefelderarray[1][7]=9;
vordefiniertefelderarray[1][8]=8;
vordefiniertefelderarray[2][2]=2;
vordefiniertefelderarray[2][3]=7;
vordefiniertefelderarray[2][6]=5;
vordefiniertefelderarray[2][8]=3;
vordefiniertefelderarray[3][1]=2;
vordefiniertefelderarray[3][4]=8;
vordefiniertefelderarray[3][5]=6;
vordefiniertefelderarray[3][8]=5;
vordefiniertefelderarray[4][2]=1;
vordefiniertefelderarray[4][6]=7;
vordefiniertefelderarray[5][1]=6;
vordefiniertefelderarray[5][2]=9;
vordefiniertefelderarray[5][3]=5;
vordefiniertefelderarray[5][5]=7;
vordefiniertefelderarray[5][6]=4;
vordefiniertefelderarray[6][2]=3;
vordefiniertefelderarray[6][4]=7;
vordefiniertefelderarray[7][0]=9;
vordefiniertefelderarray[7][2]=7;
vordefiniertefelderarray[7][5]=3;
vordefiniertefelderarray[8][1]=4;
vordefiniertefelderarray[8][2]=6;
vordefiniertefelderarray[8][3]=8;
vordefiniertefelderarray[8][4]=2;
vordefiniertefelderarray[8][5]=9;
vordefiniertefelderarray[8][7]=1;
feldausgeben(vordefiniertefelderarray);
for(int i=0;i<9;i++)
{
for(int j=0;j<9;j++)
{
sudfeld[i][j]=vordefiniertefelderarray[i][j];
}
}
solve();
feldausgeben(sudfeld);
return 0;
}
|
On August 27 2012 18:24 KainiT wrote:Hey you programming pros, i need some help as I have problems with the sudoku backtracking algorithm. I am pretty sure my other programm parts are fine and it is just the actual algorithm. Here is the code: + Show Spoiler +
void solve(int r=0, int c=0, bool forward=1) //solving algorithm
{
cout << "funktionseinstieg"<<endl; //debugging information
if(vordefiniertefelderarray[r][c]==0) //see if field is predefined
{
for(int i=0; i<9; i++)
{
cout <<"schleifenanfang"<<endl; //debugging information
sudfeld[r][c]+=1; //increase value until it fits
feldausgeben(sudfeld); //debugging information
if(!check(r,c,sudfeld[r][c] ) //see if value fits
{
cout << "check war negativ"<<endl;
if(c==8&&r==8) //solving should end here if it's already the last field
{
feldausgeben(sudfeld);
return;
}
i=9; //not really sure if i need this, probably not
if(c<8) //go to next field after right value was found
solve(r,c+1,true);
else solve(r+1,0,true);
}
else //go to previous field if right value coul not be found and set current value to 0 again
{
if(sudfeld[r][c]==9)
{
sudfeld[r][c]=0;
if(c>0)
solve(r,c-1,false);
else solve(r-1,8,false);
}
}
}
}
else //if field was predefined
{
cout<<"feldschonbelegt"; //debugging information
if(c==8&&r==8) ////solving should end here if it's already the last field
{
feldausgeben(sudfeld); //debugging information
return;
}
if(forward) //go to next field if forward value is true, previous field if not
{
if(c<8)
solve(r,c+1,true);
else solve(r+1,0,true);
}
else
{
if(c>0)
solve(r,c-1,false);
else solve(r-1,8,false);
}
}
}
I hope you don't mind to much that some function's names are in german. I commented extensively in english to make up for that. The problems appearantly start when the programm needs to go to a previous field. Possibly involving predefined values. Thanks in advance. If somebody would like to see the whole code: + Show Spoiler +
#include <iostream>
using namespace std;
int sudfeld[9][9];
int vordefiniertefelderarray[9][9];
void feldausgeben(int feld[9][9]
{
for(int i=0;i<9;i++)
{
for(int j=0;j<9;j++)
{
cout<<feld[i][j];
if(j==8)
cout << endl;
if(i==8&&j==8)
cout << endl;
}
}
}
bool box(int row, int column, int wert)
{
sudfeld[row][column]=10;
int r= (row/3)*3;
int c= (column/3)*3;
for(int i=r;i<(r+3);i++)
{
for(int j=c;j<(c+3);j++)
{
if(sudfeld[i][j]==wert)
{
cout<<"inboxgefunden";
sudfeld[row][column]=wert;
return true;
}
}
}
sudfeld[row][column]=wert;
return false;
}
bool zeile(int row,int column, int wert)
{
sudfeld[row][column]=10;
for(int i=0;(i<9);i++)
{
if(sudfeld[row][i]==wert)
{
cout<<"inzeilegefunden";
sudfeld[row][column]=wert;
return true;
}
}
sudfeld[row][column]=wert;
return false;
}
bool spalte(int row, int column, int wert)
{
sudfeld[row][column]=10;
for(int i=0;i<9;i++)
{
if(sudfeld[i][column]==wert)
{
cout<<"inspaltegefunden"<<endl;
sudfeld[row][column]=wert;
return true;
}
}
sudfeld[row][column]=wert;
return false;
}
bool check(int row, int column, int wert)
{
if(box(row,column,wert)||zeile(row,column,wert)||spalte(row,column,wert))
{
cout<<"iwogefunden"<<endl;
return true;
}
else
return false;
}
void solve(int r=0, int c=0, bool forward=1) //solving algorithm
{
cout << "funktionseinstieg"<<endl; //debugging information
if(vordefiniertefelderarray[r][c]==0) //see if field is predefined
{
for(int i=0; i<9; i++)
{
cout <<"schleifenanfang"<<endl; //debugging information
sudfeld[r][c]+=1; //increase value until it fits
feldausgeben(sudfeld); //debugging information
if(!check(r,c,sudfeld[r][c]) //see if value fits
{
cout << "check war negativ"<<endl;
if(c==8&&r==8) //solving should end here if it's already the last field
{
feldausgeben(sudfeld);
return;
}
i=9; //not really sure if i need this, probably not
if(c<8) //go to next field after right value was found
solve(r,c+1,true);
else solve(r+1,0,true);
}
else //go to previous field if right value coul not be found and set current value to 0 again
{
if(sudfeld[r][c]==9)
{
sudfeld[r][c]=0;
if(c>0)
solve(r,c-1,false);
else solve(r-1,8,false);
}
}
}
}
else //if field was predefined
{
cout<<"feldschonbelegt"; //debugging information
if(c==8&&r==8) ////solving should end here if it's already the last field
{
feldausgeben(sudfeld); //debugging information
return;
}
if(forward) //go to next field if forward value is true, previous field if not
{
if(c<8)
solve(r,c+1,true);
else solve(r+1,0,true);
}
else
{
if(c>0)
solve(r,c-1,false);
else solve(r-1,8,false);
}
}
}
int main()
{
for(int i=0;i<9;i++)
{
for(int j=0;j<9;j++)
{
sudfeld[i][j]=0;
}
}
for(int i=0;i<9;i++)
{
for(int j=0;j<9;j++)
{
vordefiniertefelderarray[i][j]=0;
}
}
vordefiniertefelderarray[0][5]=2;
vordefiniertefelderarray[1][6]=2;
vordefiniertefelderarray[1][7]=9;
vordefiniertefelderarray[1][8]=8;
vordefiniertefelderarray[2][2]=2;
vordefiniertefelderarray[2][3]=7;
vordefiniertefelderarray[2][6]=5;
vordefiniertefelderarray[2][8]=3;
vordefiniertefelderarray[3][1]=2;
vordefiniertefelderarray[3][4]=8;
vordefiniertefelderarray[3][5]=6;
vordefiniertefelderarray[3][8]=5;
vordefiniertefelderarray[4][2]=1;
vordefiniertefelderarray[4][6]=7;
vordefiniertefelderarray[5][1]=6;
vordefiniertefelderarray[5][2]=9;
vordefiniertefelderarray[5][3]=5;
vordefiniertefelderarray[5][5]=7;
vordefiniertefelderarray[5][6]=4;
vordefiniertefelderarray[6][2]=3;
vordefiniertefelderarray[6][4]=7;
vordefiniertefelderarray[7][0]=9;
vordefiniertefelderarray[7][2]=7;
vordefiniertefelderarray[7][5]=3;
vordefiniertefelderarray[8][1]=4;
vordefiniertefelderarray[8][2]=6;
vordefiniertefelderarray[8][3]=8;
vordefiniertefelderarray[8][4]=2;
vordefiniertefelderarray[8][5]=9;
vordefiniertefelderarray[8][7]=1;
feldausgeben(vordefiniertefelderarray);
for(int i=0;i<9;i++)
{
for(int j=0;j<9;j++)
{
sudfeld[i][j]=vordefiniertefelderarray[i][j];
}
}
solve();
feldausgeben(sudfeld);
return 0;
}
Well, one problem is that this is a horrible mess.
You seem to try to write a recursive solution while having no clue of how to actually use recursion. You don't backtrack in recursion, you let it do that for you.
Pseudocode since my C and C++ are a little rusty and i don't have a compiler at hand. sudoku_board is a typedef, i think char** should work for that.
+ Show Spoiler +
sudoku_board solve(sudoku_board current_state, int row, int column)
{
// Makes it easier to exit the recursion than checking all the time if it's 8/8.
if (row == 9) return current_state;
// Variable to record the solved state if found
sudoku_board *solved_state = NULL;
// If the current field is predefined, skip straight to the next
if (current_state[row][column] != 0)
{
solved_state = solve(
new_state,
((column == 8) ? row + 1 : row),
((column == 8) ? 0 : column + 1)
);
}
// We need a copy of the current state to work with inside of the recursion so we don't lose the old state
sudoku_board *new_state = copy_state(current_state);
// We test each value from 1-9
// If the recursion lead to a solution (solved_state != NULL) then we don't need to check the remaining values
for (int test_value = 1; ((test_value <= 9) && (solved_state == NULL)); ++test_value)
{
// Update the new state
new_state[row][column] = test_value;
// Check if the test value is valid
if (check_state(new_state))
{
// If it is valid, solve the next field.
solved_state = solve(
new_state,
((column == 8) ? row + 1 : row),
((column == 8) ? 0 : column + 1)
);
}
}
// Memory leaks are bad, mkay?
delete_state(new_state);
// Return any found solutions. If there are no solutions in this recursive branch, it returns the initial value NULL
return solved_state;
}
Also, why do you call one variable "vordefiniertefelderarray" and others "r" and "c". Writing "array" in the name of a variable is pointless, the name of the variable itself should already say what it is. "predefined_fields" says it's an array because, well, it's plural. And whats with your wierd bracket style? I haven't seen that outside of books about bracket styles in at least a decade. Also, skipping brackets in some situations easily leads to hard to read code like the else in this part actually belonging to another if:
+ Show Spoiler +
if(c<8) //go to next field after right value was found
solve(r,c+1,true);
else solve(r+1,0,true);
}
else //go to previous field if right value coul not be found and set current value to 0 again
{
if(sudfeld[r][c]==9)
{
sudfeld[r][c]=0;
if(c>0)
solve(r,c-1,false);
else solve(r-1,8,false);
}
}
|
Thank you for the fast answer. I definitely need that kind of help, although I hoped people wouldn't be that harsh with me :D
I'll try to implement your suggestions and then either thank you for your input or come again crying for help^^
Hmm, I gotta say that I don't get your suggestion. How exactly would this recursion do the backtracking if no value fits the current field?
Edit: I kind of get your idea now but it is a completely different algorith -.- Was hoping mine could be fixed somehow. While I know that it's a mess I would still like to know where my errors inside the mess are :D
|
On August 27 2012 19:27 KainiT wrote:
Thank you for the fast answer. I definitely need that kind of help, although I hoped people wouldn't be that harsh with me :D
I'll try to implement your suggestions and then either thank you for your input or come again crying for help^^
Hmm, I gotta say that I don't get your suggestion. How exactly would this recursion do the backtracking if no value fits the current field?
Recursion is hard to explain, it basically works that way:
solve()
|->solve()
|->solve()
|->solve()
....
If one of them doesn't find a solution, it returns NULL. That means it returns to the previous function and that then tries the next number and starts the below functions again. That is why every function call needs it's own state of the game. Once it finds a valid and completed game, it passes that down to the previous function which passes it down to it's parent, etc., until it finally arrives at the first function call.
solve(1,1)
|->1: solve(1,2) => valid
|-> 1: solve(1,3) => invalid
|-> 2: solve(1,3) => valid
|-> 1: solve(1,4) => invalid
....
|-> 1: solve(9,9) => valid, return current state
|
While I do admit obviously that my understanding of backtracking was stupid, I would still like to know why my algorithm doesn't work -.-
I will write the code like you suggested now but not knowing why the previous one didn't work is kind of destroying my nerves right now.
|
|
|
|
|
|
EPT
