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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. |
On April 26 2014 17:22 norlock wrote:Show nested quote +On April 25 2014 17:49 SilverSkyLark wrote:Hi guys Android/Java question here. I managed to set onClickListeners for my AutocompleteTextViews (ACTV) by setting it in my Java code instead of my XML one. However, my issue now is that whenever I click on any of my ACTVs, I have to click it again before the onClickFunction fires successfully. In my onCreate, I initialize my ACTVs as such:
brandACTV = (AutoCompleteTextView) findViewById(R.id.actvBrand);
itemACTV = (AutoCompleteTextView) findViewById(R.id.actvItemName);
partACTV = (AutoCompleteTextView) findViewById(R.id.actvPart);
barcodeACTV = (AutoCompleteTextView) findViewById(R.id.actvBarcode);
brandACTV.setOnClickListener(actvClicked);
itemACTV.setOnClickListener(actvClicked);
partACTV.setOnClickListener(actvClicked);
barcodeACTV.setOnClickListener(actvClicked);
and I create my onClickListener function as such:
OnClickListener actvClicked = new OnClickListener(){
@Override
public void onClick(View view){
switch (view.getId()) {
case R.id.actvBrand:
Log.d("Hi", "Brand pressed");
break;
case R.id.actvItemName:
Log.d("Hi", "Item name pressed");
break;
case R.id.actvPart:
Log.d("Hi", "Part pressed");
break;
case R.id.actvBarcode:
Log.d("Hi", "Barcode pressed");
break;
}
}
};
Any ideas anyone? your code is wrong. You can't use it on a anonymous class, you need to create a private class. example from internet.
package com.example.android.accelerometerplay;
import android.app.Activity;
import android.view.View;
import android.view.View.OnClickListener;
import android.os.Bundle;
import android.widget.Button;
import android.widget.Toast;
import android.content.Context;
public class StudentFormsActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// To specify the actions of the Buttons
Button accept = (Button) findViewById(R.id.myButton1);
Button reject = (Button) findViewById(R.id.myButton2);
accept.setOnClickListener(clickFunction);
reject.setOnClickListener(clickFunction);
}
private OnClickListener clickFunction = new OnClickClass();
private class OnClickClass implements OnClickListener{
public void onClick(View v){
Context context = getApplicationContext();
CharSequence text;
switch(v.getId()){
case R.id.myButton1: text="accept was pushed";
break;
case R.id.myButton2: text="reject was pushed";
break;
default: text="We didn't know what was pressed :(";
}
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context,text,duration);
toast.show();
}
}
}
I think he stated already that the problem was something else, but even if not, this advice is wrong. The only difference between the anonymous inner class and a named innerclass is that you can construct a named inner class more than once.
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Hey guys, got a small question here in search of a better way of coding something.
What I'm doing here in this code is I'm checking whether the codedPinArray value at slot k matches the value for the code array at the slot of pinArray at value k. I got it all synced up and stuff, which took me a while to wrap my head around nesting an array inside an array, so that's not a problem.
Here be code:
+ Show Spoiler + for (int k = 0; k < 5; k++)
{
if (codedPinArray[k] == code[pinArray[k]])
{
isMatch = true;
}
}
What I want to do is have this code go through each number and, if each number matches, set (bool) isMatch equal to true. The problem is, if any of the 5 numbers match, even if the other 4 or so don't, it will still set isMatch = true. I want it so that only is all the numbers match, isMatch = true.
I know I can do this if I did this instead:
+ Show Spoiler +if (codedPinArray[0] == code[pinArray[0]] &&
codedPinArray[1] == code[pinArray[1]] &&
codedPinArray[2] == code[pinArray[2]] &&
codedPinArray[3] == code[pinArray[3]] &&
codedPinArray[4] == code[pinArray[4]])
{
isgood = true;
}
That'll work fine for my purposes on this assignment I've got. There's nothing saying I can't do that, but I was just wondering if there was a better way. Like, what if I had to check matches for a thousand values in the array or something? How might I use that in the for loop above? Thanks.
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One idea would be to create to create a boolean array in which each index lines up with your code/codedPinArray indices. If the two array items match, the matching boolean array index is set to true. Then to solve your issue of if they all match, just have a loop of some type that checks if all entries in the boolean array are true. If one is false, set a separate boolean variable to false and return that instead. It's also handy because if a set doesn't match, you can always output the results of the boolean array to find which don't match.
Like so (I'm attempting to do this in C++, but my C++ is super rusty so it is kinda pseudocody. You should get what I mean though):
bool isMatched[5];
for (int k = 0; k < 5; k++)
{
if (codedPinArray[k] == code[pinArray[k]])
{
isMatched[k] = true;
}
}
bool allMatch = true;
for (int i = 0; i < 5; i++)
{
if (!isMatched[i]) allMatch = false; // can also use isMatched[i] == false in the if statement
}
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Great idea! Thanks. Never had to use a bool array before but I think this should work just fine.
Edit: Actually I just thought of an easier way without using bool arrays.
I can increase the count of something each time that number matches. Then if that count is == 5, I will know that the numbers match.
Something like this
+ Show Spoiler +
int amount = 0;
for (int k = 0; k < 5; k++)
{
if (codedPinArray[k] == code[pinArray[k]])
{
amount++;
}
}
if (amount == 5)
{
//do this
}
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Since your success condition is all matching elements, you only need to find a single mismatch to know the condition cannot be met. If you have a million pairs and the first doesn't match then you can stop right away.
bool allMatch = true;
for (int k = 0; k < CODE_SIZE; k++)
{
if (codedPinArray[k] != code[pinArray[k]])
{
allMatch = false;
break;
}
}
if (allMatch)
{
takeAction();
}
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On April 27 2014 13:53 Mstring wrote:Since your success condition is all matching elements, you only need to find a single mismatch to know the condition cannot be met. If you have a million pairs and the first doesn't match then you can stop right away.
bool allMatch = true;
for (int k = 0; k < CODE_SIZE; k++)
{
if (codedPinArray[k] != code[pinArray[k]])
{
allMatch = false;
break;
}
}
if (allMatch)
{
takeAction();
}
That's even easier. Good idea. I've had my head stuck in data structures for too long and have a tendency to complicate things a bit too much. Stupid shortest path algorithms and things like that can use boolean arrays.
I guess my solution is more useful for finding pairs that don't match.
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bool isMatch = true;
for (int k = 0; k < 5; k++) {
isMatch = isMatch && (codedPinArray[k] == code[pinArray[k]]);
}
These things always turn into code golf
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Extract a function from Mstring's solution and you have a very clear piece of code:
bool PinArraysMatch(int[] codedPinArray, int[] pinArray, int[] code, int length)
{
for(int k = 0; k < length; ++k)
{
if(codedPinArray[k] != code[pinArray[k]])
{
return false;
}
}
return true;
}
This actually closely resembles functions like Linq's All() or Any() (based on an enumeration of ints from 0 to length). So if your language supports lambdas, chances are there already is a function that does exactly what you want if you give it the right input.
In short: Any() and All() check whether a condtion holds true for any or all elements in a list of elements, and that's exactly what you want to know: Are there any elements that don't match. You just have to create the list properly.
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On April 27 2014 15:41 spinesheath wrote:Extract a function from Mstring's solution and you have a very clear piece of code: bool PinArraysMatch(int[] codedPinArray, int[] pinArray, int[] code, int length)
{
for(int k = 0; k < length; ++k)
{
if(codedPinArray[k] != code[pinArray[k]])
{
return false;
}
}
return true;
}
This actually closely resembles functions like Linq's All() or Any() (based on an enumeration of ints from 0 to length). So if your language supports lambdas, chances are there already is a function that does exactly what you want if you give it the right input. In short: Any() and All() check whether a condtion holds true for any or all elements in a list of elements, and that's exactly what you want to know: Are there any elements that don't match. You just have to create the list properly.
Any() and All() won't do. I think that the order here is important, if it wasn't he would use foreach instead of for.
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var hasMismatch = Enumerable.Range(0, length).Any(k => codedPinArray[k] != code[pinArray[k]]);
You can't enumerate directly on the arrays, but you can enumerate on the index.
You could also create a sequence of pairs at first and then call Any() on that, like this:
IEnumerable<Tuple<int, int>> GetPairSequence(int[] codedPinArray, int[] pinArray, int[] code)
{
for(int k = 0; k < codedPinArray.Length; ++k)
{
yield return Tuple.Create(codedPinArray[k], code[pinArray[k]]);
}
}
...
var hasMismatch = GetPairSequence.Any(pair => pair.Item1 != pair.Item2);
But I would only really do that if there were other places that could make use of the sequence of pairs. Also C#'s Tuple class is really awkward, I'd prefer not to use it at all. "Item1" and "Item2" isn't exacly self-documenting code.
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code golf! using mismatch and a lambda. hoping i understood the problem.
typedef array<int,5> array_t;
//dummy variables
array_t pin{0,1,2,3,4};
array_t code{4,3,2,1,0};
array_t coded_pin{4,3,2,1,0};
bool match=mismatch(
begin(coded_pin),
end(coded_pin),
begin(pin),
[&code](int const& coded_pin_digit,int const& code_idx){
return coded_pin_digit==code[code_idx];
}
).first==end(coded_pin);
|
Hi all,
I've got some coding homework to design an acoustic sensor. When it detects noise level changes, it sends notifications to all devices listening to it. There are 2 other devices listening, which include a warning light and a self destruct, which both due their own thing depending on the noise level. I'm trying to approach this problem in OOP, but have trouble thinking in abstract. I have narrowed down the "classes" as nouns, which are the sensor, warning light and self destruct device, and can list their responsibilities. Any hints on what I can do next, or even design patterns that I can follow would be greatly appreciated.
I am coding in C#.net.
Thanks!
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On April 27 2014 03:53 berated- wrote:Show nested quote +On April 26 2014 17:22 norlock wrote:On April 25 2014 17:49 SilverSkyLark wrote:Hi guys Android/Java question here. I managed to set onClickListeners for my AutocompleteTextViews (ACTV) by setting it in my Java code instead of my XML one. However, my issue now is that whenever I click on any of my ACTVs, I have to click it again before the onClickFunction fires successfully. In my onCreate, I initialize my ACTVs as such:
brandACTV = (AutoCompleteTextView) findViewById(R.id.actvBrand);
itemACTV = (AutoCompleteTextView) findViewById(R.id.actvItemName);
partACTV = (AutoCompleteTextView) findViewById(R.id.actvPart);
barcodeACTV = (AutoCompleteTextView) findViewById(R.id.actvBarcode);
brandACTV.setOnClickListener(actvClicked);
itemACTV.setOnClickListener(actvClicked);
partACTV.setOnClickListener(actvClicked);
barcodeACTV.setOnClickListener(actvClicked);
and I create my onClickListener function as such:
OnClickListener actvClicked = new OnClickListener(){
@Override
public void onClick(View view){
switch (view.getId()) {
case R.id.actvBrand:
Log.d("Hi", "Brand pressed");
break;
case R.id.actvItemName:
Log.d("Hi", "Item name pressed");
break;
case R.id.actvPart:
Log.d("Hi", "Part pressed");
break;
case R.id.actvBarcode:
Log.d("Hi", "Barcode pressed");
break;
}
}
};
Any ideas anyone? your code is wrong. You can't use it on a anonymous class, you need to create a private class. example from internet.
package com.example.android.accelerometerplay;
import android.app.Activity;
import android.view.View;
import android.view.View.OnClickListener;
import android.os.Bundle;
import android.widget.Button;
import android.widget.Toast;
import android.content.Context;
public class StudentFormsActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// To specify the actions of the Buttons
Button accept = (Button) findViewById(R.id.myButton1);
Button reject = (Button) findViewById(R.id.myButton2);
accept.setOnClickListener(clickFunction);
reject.setOnClickListener(clickFunction);
}
private OnClickListener clickFunction = new OnClickClass();
private class OnClickClass implements OnClickListener{
public void onClick(View v){
Context context = getApplicationContext();
CharSequence text;
switch(v.getId()){
case R.id.myButton1: text="accept was pushed";
break;
case R.id.myButton2: text="reject was pushed";
break;
default: text="We didn't know what was pressed :(";
}
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context,text,duration);
toast.show();
}
}
}
I think he stated already that the problem was something else, but even if not, this advice is wrong. The only difference between the anonymous inner class and a named innerclass is that you can construct a named inner class more than once.
http://stackoverflow.com/questions/9017374/private-onclicklistener-clickfunction-new-onclicklistenerstmt <-- This is why you do it. you put multiple objects, on a class so STILL USE A PRIVATE CLASS! And you don't construct a class more than once but objects.
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On April 28 2014 02:53 novaballistix wrote:
Hi all,
I've got some coding homework to design an acoustic sensor. When it detects noise level changes, it sends notifications to all devices listening to it. There are 2 other devices listening, which include a warning light and a self destruct, which both due their own thing depending on the noise level. I'm trying to approach this problem in OOP, but have trouble thinking in abstract. I have narrowed down the "classes" as nouns, which are the sensor, warning light and self destruct device, and can list their responsibilities. Any hints on what I can do next, or even design patterns that I can follow would be greatly appreciated.
I am coding in C#.net.
Thanks!
I suggest you look up C# events and/or the INotifyPropertyChanged interface.
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On April 28 2014 03:12 spinesheath wrote:Show nested quote +On April 28 2014 02:53 novaballistix wrote:
Hi all,
I've got some coding homework to design an acoustic sensor. When it detects noise level changes, it sends notifications to all devices listening to it. There are 2 other devices listening, which include a warning light and a self destruct, which both due their own thing depending on the noise level. I'm trying to approach this problem in OOP, but have trouble thinking in abstract. I have narrowed down the "classes" as nouns, which are the sensor, warning light and self destruct device, and can list their responsibilities. Any hints on what I can do next, or even design patterns that I can follow would be greatly appreciated.
I am coding in C#.net.
Thanks! I suggest you look up C# events and/or the INotifyPropertyChanged interface.
I forgot to mention that I am unable to use the event keyword. I dont think I can use INotigyPropertyChanged as it uses the PropertyChanged Event. Correct me if i'm wrong, thanks
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On April 28 2014 03:31 novaballistix wrote:Show nested quote +On April 28 2014 03:12 spinesheath wrote:On April 28 2014 02:53 novaballistix wrote:
Hi all,
I've got some coding homework to design an acoustic sensor. When it detects noise level changes, it sends notifications to all devices listening to it. There are 2 other devices listening, which include a warning light and a self destruct, which both due their own thing depending on the noise level. I'm trying to approach this problem in OOP, but have trouble thinking in abstract. I have narrowed down the "classes" as nouns, which are the sensor, warning light and self destruct device, and can list their responsibilities. Any hints on what I can do next, or even design patterns that I can follow would be greatly appreciated.
I am coding in C#.net.
Thanks! I suggest you look up C# events and/or the INotifyPropertyChanged interface. I forgot to mention that I am unable to use the event keyword. I dont think I can use INotigyPropertyChanged as it uses the PropertyChanged Event. Correct me if i'm wrong, thanks
In that case you can take a look at Action<> and Func<>
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On April 28 2014 03:31 novaballistix wrote:Show nested quote +On April 28 2014 03:12 spinesheath wrote:On April 28 2014 02:53 novaballistix wrote:
Hi all,
I've got some coding homework to design an acoustic sensor. When it detects noise level changes, it sends notifications to all devices listening to it. There are 2 other devices listening, which include a warning light and a self destruct, which both due their own thing depending on the noise level. I'm trying to approach this problem in OOP, but have trouble thinking in abstract. I have narrowed down the "classes" as nouns, which are the sensor, warning light and self destruct device, and can list their responsibilities. Any hints on what I can do next, or even design patterns that I can follow would be greatly appreciated.
I am coding in C#.net.
Thanks! I suggest you look up C# events and/or the INotifyPropertyChanged interface. I forgot to mention that I am unable to use the event keyword. I dont think I can use INotigyPropertyChanged as it uses the PropertyChanged Event. Correct me if i'm wrong, thanks
Well, in that case you just code that behaviour yourself. Seems like that's the goal of the exercise...
Check out the Observer and Publish/Subscribe patterns.
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I have a programming challenge I can't quite seem to get the right awnser to, it goes like this
You were hired by a director of a small company with N employees to set up the network between the employees who have to send a weekly report to each of the other employees as a different part or their report is important for each employee, depending on the importance of their work they have to send a report Ki number of times per week
You have measured the time it takes for a message to be delivered between each 2 employees
Due to budget cuts the network will only have N-1 connections between they employees and because of the simplicity of the technology you are using when one message is sent the entire network has to wait for it to be delivered (only 1 message at a time)
What you get is N -the number of employees, you get Ki which is the muber of times a report from worker i is to be sent per week, Tij which indicates the time a message traveles from employee i to employee j
1<=N<=13
0<=Ki<=10^3
0<=Tij<=10^3
Tij = Tji, Tii = 0
At first I assumed the most optimal network would be a star (tree) and all it would take is to determine which node to be in the center and since we were limited to an N at most 13 I decided to just brute force it and try them all, but that attempt failed as apparently this was not the most optimal network configuration (or so the test cases showed me)
Then I thought maybe this would be solved by finding a minimum spanning tree or each full graph made from the employees, but since there are multiple minimum spanning trees and not all of them are equaly good for this problem that failed on paper already
I am currently a bit out of ideas, so a hint as to what direction I should be looking towards would be great
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Maybe I'm stupid, but I don't understand the programming challenge here.
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If my resulting graph has no edge from employee a to employee b, but edges from a to c and from c to b, is the time from a to b defined as Tab or as Tac + Tcb?
Our graph is always a tree. It has to be connected or else one employee couldn't message everyone else. It has N nodes and N-1 edges. Therefore it is a tree, and we are most likely looking for a Minimum Spanning Tree by some weight function we don't know yet.
We know that in our resulting tree, every edge is used Sum Ki = K times to send all messages since each employee a recieves Kb messages from each other emplyee b and sends Ka messages himself.That's wrong, explanation in another post.
It seems fairly obvious that we need to weigh the edges by a combination of Tij and Ki. But since each edge is used K times, maybe Ki actually isn't relevant at all.
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EPT
