• Log InLog In
  • Register
Liquid`
Team Liquid Liquipedia
EDT 16:39
CEST 22:39
KST 05:39
  • Home
  • Forum
  • Calendar
  • Streams
  • Liquipedia
  • Features
  • Store
  • EPT
  • TL+
  • StarCraft 2
  • Brood War
  • Smash
  • Heroes
  • Counter-Strike
  • Overwatch
  • Liquibet
  • Fantasy StarCraft
  • TLPD
  • StarCraft 2
  • Brood War
  • Blogs
Forum Sidebar
Events/Features
News
Featured News
[ASL22] Ro24 Preview: Summer's End9Serral wins HomeStory Cup 2915Serral wins Maestros of the Game 244ByuL, and the Limitations of Standard Play3Team Liquid Map Contest #22: Results and Winners7
Community News
Weekly Cups (August 10-16): SHIN doubles2GSTL Returns in 2026!45Weekly Cups (Aug 3-9): Protoss get shut out7RSL goes to London! 2026 Offline Finals Nov 21-2212Weekly Cups (July 27-Aug 2): SHIN's big week0
StarCraft 2
General
Geoff 'iNcontroL' Robinson has passed away SC4ALL II: SC2 Player Announcement 6/8 - Maru GSTL Returns in 2026! Balance hotfix patch 5.0.16b (July 16) Serral wins Maestros of the Game 2
Tourneys
PIG STY FESTIVAL 8.0! (13 - 23 August) WORTEX 2026 - Hungarian SC2 Finals Budapest Sparkling Tuna Cup - Weekly Open Tournament SC2 AI Tournament 2026 Fall 2026 GSTL Announcement
Strategy
[G] Having the right mentality to improve
Custom Maps
Nexus Wars 2021 GUIDE [M] (2) Industrial Park
External Content
The PondCast: SC2 News & Results Mutation # 539 Thunder Dome Mutation # 538 Media Blackout Mutation # 537 Hostile Territory
Brood War
General
Pros React To: First 'Fastest' Map in ASL History BW General Discussion [Personal Project Share] Terran Defense v0.60 ASL22 General Discussion BGH Auto Balance -> http://bghmmr.eu/
Tourneys
Toronto invitational lan 22 august [ASL22] Ro24 Group A [ASL22] Ro24 Group B Brood War in Budapest ! WORTEX 2026 BW Finals
Strategy
Odyssey Mineral Stack Saturation Fighting Spirit mining rates Any training maps people recommend? Simple Questions, Simple Answers
Other Games
General Games
Nintendo Switch Thread General RTS Discussion Thread Anyone here play Quakeworld back in the day? Stormgate/Frost Giant Megathread EVE Corporation
Dota 2
Official 'what is Dota anymore' discussion
League of Legends
[TL LoL EUW IHs] Teemo shall perish TSM pausing esports and CLG Dead
Heroes of the Storm
Heroes of the Storm 2.0
Hearthstone
Deck construction bug
TL Mafia
TL Mafia Power Rank TL Mafia Community Thread NeO.D_StephenKing vs This Guy From 1 Million Dance
Community
General
US Politics Mega-thread Russo-Ukrainian War Thread Canadian Politics Mega-thread Dating: How's your luck? Artificial Intelligence Thread
Fan Clubs
The Creator Fan Club MarineLorD Fan Club The ShoWTimE Fan Club
Media & Entertainment
Movie Discussion! Anime Discussion Thread
Sports
MLB/Baseball 2023 Football (Soccer) Thread TeamLiquid Health and Fitness Initiative For 2023 NBA General Discussion
World Cup 2022
Tech Support
Computer Build, Upgrade & Buying Resource Thread Simple Questions Simple Answers FPS when play League Of Legend on laptop
TL Community
The Automated Ban List Northern Ireland Global Starcraft
Blogs
Young Players Exit Esports E…
TrAiDoS
LOCKPICKING NOOB
LUCKY_NOOB
Cathedral Of CS And NY pizza a…
FuDDx
Please support my new stand…
Peanutsc
Customize Sidebar...

Website Feedback

Closed Threads



Active: 5855 users

C++ noob question

Blogs > eMbrace
Post a Reply
1 2 Next All
eMbrace
Profile Blog Joined January 2009
United States1300 Posts
Last Edited: 2009-10-17 02:49:29
October 17 2009 02:48 GMT
#1
I've been doing quite well in my class, but I've finally hit something that I can't figure out.

Basically, we have to decode a text file back to english (Caesar Cipher), and we have to run the text file through the our progame via the Command Prompt.

I've finished writing my code, but I can't get it to feed me back any output -- wrong or right.

I don't get an error or anything just this:

(checking to see if files I need are there, they are)
+ Show Spoiler +
[image loading]


(running the txt file through my program, maybe?)
+ Show Spoiler +
[image loading]


As you can see, nothing happens, and no errors appear either.

thats how I was instructed to do it and it's worked once before the other day, but now I finished writing my code and I can't test it =/

If you feel like taking the time, you can look at that as well:

+ Show Spoiler +
#include <iostream>
#include <iomanip>
#include <math.h>



using namespace std;


char reverseCaesar( char ch );
char convPunct( char ch );
char convDigit( char ch );
char convRest(char ch);
//***************************************************************************************************************************
int main()
{
char ch;
int change;


cin >> ch;

while ( cin )
{
char change;
if( isalpha(ch) )
{
change = reverseCaesar(ch);

}
else if (ispunct(ch) )
{
change = convPunct(ch);

}
else if (isdigit(ch) )
{
change = convDigit(ch);

}

else
change = convRest(ch);

cin >> ch;
}


system ("pause");
return 0;
}

//***************************************************************************************************************************

char reverseCaesar( char ch )
{
int i;

if (ch <= 47 && ch > 44)
{
i = (int)ch + 23;
}
else if (ch <=99 && ch > 96)
{
i = (int)ch +23;
}
else

i = (int)ch - 3;

return char(i);
}

char convPunct( char ch )
{
switch(ch)
{
case ',': return '0';
break;
case '.': return '1';
break;
case '$': return '2';
break;
case '&': return '3';
break;
case '%': return '4';
break;
case '*': return '5';
break;
case '(': return '6';
break;
case ')': return '7';
break;
case '?': return '8';
break;
case '!': return '9';

default: return ch;

}
}

char convDigit( char ch )
{
switch(ch)
{
case '0': return '!';
break;
case '1': return ',';
break;
case '2': return ')';
break;
case '3': return '(';
break;
case '4': return '?';
break;
case '5': return '-';
break;
case '6': return '&';
break;
case '7': return '$';
break;
case '8': return '.';
break;
case '9': return '+';
break;

default: return ch;

}
}

char convRest(char ch)
{
if(ch==21)
ch='\n';
else if(ch==22)
ch=' ';
else
ch=ch;

return ch;
}


I haven't added documentation, but it's fairly straight forward -- taking the characters from the txt file and decoding them (we had to write and use our own functions as well).

I'm willing to bet my program wouldn't work even if I could see it, but i'd at least like to try.

any help would appreciated, it's due in a couple of hours =)

if I have to i'll just submit and see if I can edit and resubmit tomorrow .

thanks.







*
Shade692003
Profile Joined August 2005
Canada702 Posts
October 17 2009 02:58 GMT
#2
been pretty long since I've done anything like coding or w/e, but if I understand correctly you enter your text file path as a parameter for your program? shouldn't there be parameters in your main then?
I hate the post below mine because it feels War3-ish.
DrTJEckleburg
Profile Blog Joined February 2009
United States1080 Posts
October 17 2009 02:58 GMT
#3
I have no help for your question, but I do believe that your reign at the top of LB will end after you bet on MBC over KT Rolster.
Im pretty good at whistling with my hands, especially when Im holding a whistle.
paper
Profile Blog Joined September 2004
13196 Posts
Last Edited: 2009-10-17 02:59:19
October 17 2009 02:59 GMT
#4
[image loading]


voting for MBC is your problem


edit: YOU GUYS ARE TOO FAST
Hates FunπŸ€”
keV.
Profile Blog Joined February 2009
United States3214 Posts
Last Edited: 2009-10-17 03:04:04
October 17 2009 03:00 GMT
#5
Wait a minute something isn't right here.


I'm pretty sure you can't read a txt file with cin, while expecting a char.

I don't know the details of your assignment, but do you take the file you are reading from as a parameter? If you do, then you definitely need to take some command line arguments. If not, then you can just open the file in your main or accept it by input string, and read char by char until the end of file.
"brevity is the soul of wit" - William Shakesman
AcrossFiveJulys
Profile Blog Joined September 2005
United States3612 Posts
Last Edited: 2009-10-17 03:05:10
October 17 2009 03:01 GMT
#6
I'm a little confused about what you're asking, but I think you are asking why your program doesn't "do" anything when you run it. Okay, so given that...

Your second screenshot shows you running the program with the file as input correctly.

Now, your program doesn't produce any output on the command prompt because you aren't telling it to print anything. Use cout if you want to print messages to the command prompt. If you are trying to create a new file that contains the translation of the original file, you'll need to use an ofstream and output to that, or use "> some_file" when running the program and print to some_file using cout.

eMbrace
Profile Blog Joined January 2009
United States1300 Posts
October 17 2009 03:01 GMT
#7
On October 17 2009 11:58 DrTJEckleburg wrote:
I have no help for your question, but I do believe that your reign at the top of LB will end after you bet on MBC over KT Rolster.


i'm on top for a reason
AcrossFiveJulys
Profile Blog Joined September 2005
United States3612 Posts
October 17 2009 03:03 GMT
#8
On October 17 2009 12:00 keV. wrote:
Wait a minute something isn't right here.


I'm pretty sure you can't read a txt file with cin, while expecting a char.


Yes you can. Since he's using the "<" operator when running the program, it changes the stdin stream (which is what cin uses) to refer to the file instead of user input.
Shade692003
Profile Joined August 2005
Canada702 Posts
October 17 2009 03:03 GMT
#9
On October 17 2009 12:00 keV. wrote:
Wait a minute something isn't right here.


I'm pretty sure you can't read a txt file with cin, while expecting a char.



I think the cin are for reading the characters in the text files, once they are read he changes them according to their values. could be wrong tho.

Anyhow there is no output like the other guy said
I hate the post below mine because it feels War3-ish.
eMbrace
Profile Blog Joined January 2009
United States1300 Posts
October 17 2009 03:05 GMT
#10
On October 17 2009 12:01 AcrossFiveJulys wrote:
I'm a little confused about what you're asking, but I think you are asking why your program doesn't "do" anything when you run it. Okay, so given that...

Your second screenshot shows you running the program with the file as input correctly.

Now, your program doesn't produce any output on the command prompt because you aren't telling it to print anything. Use cout if you want to print messages to the command prompt. If you are trying to create a new file that contains the translation of the original file, you'll need to use an ofstream and output to that.



to put it into a new file, they taught us this format

program < input.txt > new.txt

i get a new file with nothing in it =/
Shade692003
Profile Joined August 2005
Canada702 Posts
Last Edited: 2009-10-17 03:06:46
October 17 2009 03:05 GMT
#11
So hmm, shoudn't you cout that ''change'' variable?

Edit: Try to cout the change variable at the end of the while loop, might cout the value into the new text file.
I hate the post below mine because it feels War3-ish.
keV.
Profile Blog Joined February 2009
United States3214 Posts
Last Edited: 2009-10-17 03:06:53
October 17 2009 03:05 GMT
#12
On October 17 2009 12:03 AcrossFiveJulys wrote:
Show nested quote +
On October 17 2009 12:00 keV. wrote:
Wait a minute something isn't right here.


I'm pretty sure you can't read a txt file with cin, while expecting a char.


Yes you can. Since he's using the "<" operator when running the program, it changes the stdin stream (which is what cin uses) to refer to the file instead of user input.


I don't think reading from a file without a file handle is a good idea.

its sad how long its been since I've worked with simple I/O input...
"brevity is the soul of wit" - William Shakesman
vAltyR
Profile Blog Joined July 2008
United States581 Posts
Last Edited: 2009-10-17 03:08:40
October 17 2009 03:05 GMT
#13
Commenting is your best friend. Especially when you're asking others to help with your program. I didn't think it'd make that much difference, but I've had time where I look back on code and think "wtf was I doing here again?"

Do you need to separate it into functions like that? Sometimes it gets confusing debugging so many functions, especially when the code isn't your own.


EDIT: Wait a second... You're reading this from a file, right? You have nothing set up for file IO.
λ‚΄ ν˜Έλ²„ν¬λΌν”„νŠΈλŠ” μž₯μ–΄λ‘œ 가득 μ°¨ μžˆμ–΄μš”
Ironson
Profile Joined February 2008
20 Posts
October 17 2009 03:06 GMT
#14
The program is well formed, but it doesn't output anything! You need to write the output to "cout" and stream it into a file. Your command would become something like: pgm6 < input.txt > output.txt
keV.
Profile Blog Joined February 2009
United States3214 Posts
October 17 2009 03:07 GMT
#15
Like whats been said in this thread, you need to either rewrite the original file as you read char by char or you need to print the output to a a new file or screen.
"brevity is the soul of wit" - William Shakesman
eMbrace
Profile Blog Joined January 2009
United States1300 Posts
Last Edited: 2009-10-17 03:09:14
October 17 2009 03:08 GMT
#16
On October 17 2009 12:06 Ironson wrote:
The program is well formed, but it doesn't output anything! You need to write the output to "cout" and stream it into a file. Your command would become something like: pgm6 < input.txt > output.txt


ok right, but how exactly do I make my program cout all the decoded characters at once after the loop is over?

and sorry for the code with out comments -- we did have to write functions to use in the main, i guess it's a way of them making us learn how they work.



Ironson
Profile Joined February 2008
20 Posts
October 17 2009 03:09 GMT
#17
Before your second "cin >> ch;", place "cout << change;".
eMbrace
Profile Blog Joined January 2009
United States1300 Posts
Last Edited: 2009-10-17 03:14:24
October 17 2009 03:13 GMT
#18
On October 17 2009 12:09 Ironson wrote:
Before your second "cin >> ch;", place "cout << change;".



woah, it worked.

got all the decoded next in a new file.

thanks a lot everyone -- you may have saved my A in this class.

now I can watch MBC just roll over KT tonight
keV.
Profile Blog Joined February 2009
United States3214 Posts
October 17 2009 03:13 GMT
#19
this should give you simple error checking output.

+ Show Spoiler +

int main()
{
char ch;
int change;


cin >> ch;

while ( cin )
{
char change;
if( isalpha(ch) )
{
change = reverseCaesar(ch);


}
else if (ispunct(ch) )
{
change = convPunct(ch);


}
else if (isdigit(ch) )
{
change = convDigit(ch);


}

else
change = convRest(ch);
//output goes here

cin >> ch;
}


system ("pause");
return 0;
}

"brevity is the soul of wit" - William Shakesman
eMbrace
Profile Blog Joined January 2009
United States1300 Posts
October 17 2009 03:17 GMT
#20
On October 17 2009 12:13 keV. wrote:
this should give you simple error checking output.

+ Show Spoiler +

int main()
{
char ch;
int change;


cin >> ch;

while ( cin )
{
char change;
if( isalpha(ch) )
{
change = reverseCaesar(ch);


}
else if (ispunct(ch) )
{
change = convPunct(ch);


}
else if (isdigit(ch) )
{
change = convDigit(ch);


}

else
change = convRest(ch);
//output goes here

cin >> ch;
}


system ("pause");
return 0;
}



thanks a bunch kev
1 2 Next All
Please log in or register to reply.
Live Events Refresh
Patches Events
16:00
Berry Patch Open #2
RotterdaM1377
Liquipedia
[ Submit Event ]
Live Streams
Refresh
StarCraft 2
RotterdaM 1377
ProTech114
Railgan 44
EnDerr 3
StarCraft: Brood War
Calm 3003
Artosis 1193
Mini 186
Barracks 49
scan(afreeca) 22
Hm[arnc] 16
Dota 2
qojqva4214
febbydoto11
League of Legends
Doublelift3102
JimRising 223
Super Smash Bros
Mew2King97
Heroes of the Storm
Liquid`Hasu467
Other Games
Grubby2498
FrodaN981
Chillindude25
MindelVK4
Organizations
Other Games
gamesdonequick1170
EGCTV1148
BasetradeTV63
StarCraft 2
angryscii 19
[ Show 13 non-featured ]
StarCraft 2
• Berry_CruncH123
• printf 22
• AfreecaTV YouTube
• intothetv
• Kozan
• IndyKCrew
• Migwel
StarCraft: Brood War
• BSLYoutube
• STPLYoutube
• ZZZeroYoutube
Other Games
• Scarra728
• Shiphtur296
• tFFMrPink 15
Upcoming Events
Sparkling Tuna Cup
13h 21m
PiG Sty Festival
15h 21m
Solar vs Reynor
Serral vs TBD
OSC
19h 21m
Afreeca Starleague
1d 13h
hero vs ggaemo
Larva vs Mong
The Patches Monday
1d 19h
Afreeca Starleague
2 days
Soulkey vs PianO
JyJ vs sSak
GSL
2 days
PiGosaur Cup
3 days
Replay Cast
3 days
Afreeca Starleague
3 days
Mini vs Calm
Queen vs EffOrt
[ Show More ]
Replay Cast
4 days
The PondCast
4 days
IntoTheTV X SOOP
5 days
GSL
6 days
Liquipedia Results

Completed

Escore Tournament S3: W8
CranK Gathers Season 4: BW vs SC2 Team League
Eternal Conflict S2 Finale

Ongoing

KCM Race Survival 2026 Season 3
K-JUNGMAN
ASL Season 22
Super Anchor Qualifying S3
CSL Season 22: Qualifier 1
RSL Revival: Season 6
PiG Sty Festival 8.0
META DYMY #4
Esports World Cup 2026
Esports World Cup 2026: LCQ
BLAST Bounty Summer 2026
BLAST Bounty Summer Qual
Stake Ranked Episode 3
XSE Pro League 2026
IEM Cologne Major 2026

Upcoming

CSL Season 22: Qualifier 2
CSL 2026 AUTUMN (S22)
Acropolis #5
Acropolis #5 - TRS
Blizzard Classic Cup 2026
Acropolis #5 - GSA
Acropolis #5 - GSB
HSC XXX
SC4ALL II: StarCraft II
Kung Fu Cup 2026 Grand Finals
RSL Offline Finals
Calamity Invitational
Big Dog Cup 2026 Div 1
IEM Beijing 2026
Stake Ranked Episode 5
PGL Masters Bucharest 2026
Thunderpick World Champ. '26
ESL Pro League Season 24
Stake Ranked Episode 4
1win Private Club #1
Logitech G Play Connect 2026
SL StarSeries Fall 2026
FISSURE Playground #3
BLAST Open Fall 2026
TLPD

1. ByuN
2. TY
3. Dark
4. Solar
5. Stats
6. Nerchio
7. sOs
8. soO
9. INnoVation
10. Elazer
1. Rain
2. Flash
3. EffOrt
4. Last
5. Bisu
6. Soulkey
7. Mini
8. Sharp
Sidebar Settings...

Advertising | Privacy Policy | Terms Of Use | Contact Us

Original banner artwork: Jim Warren
The contents of this webpage are copyright © 2026 TLnet. All Rights Reserved.