2d arrays, setting values doesnt work

**Isnalla** · 02-18-2012

im doing a battleship game program for my project.

here's my code so far

Code:

#include <stdio.h>#include <stdlib.h>
#include <string.h>


int main_menu(char board1[10][10],char board2[10][10]){
    int choice;
    printf(" \n_____________\n");
    printf("|--Main Menu--|\n");
    printf("|             |\n");
	printf("|[1]Game Start|\n");            //print main menu
	printf("|[2]Logout    |\n");
    printf(" ~~~~~~~~~~~~~\n\n");


    do{
        printf("Enter Choice: ");
        scanf("%d",&choice);
        if (choice==2) {
            return 0;
        }
        else if (choice!=1){
            printf("Choice invalid!\n");
        }
    }while(choice!=2 && choice!=1);
    do{
    printf("\n[1]Single Player\n");
    printf("[2]Multiplayer\n");
    printf("[3]Go back\n");
    scanf("%d", &choice);
       switch(choice){
            case 1:
                setBoard1(board1,board2);
                printBoard1(board1,board2);
                setShip(board1,board2);
                break;
            case 2:
                return 0;
                break;
            case 3:
                main_menu(board1,board2);
                break;
            default:printf("Choice invalid!");
                break;
       }
    }while(choice!=3);
}


int setBoard1(char board1[10][10], char board2[10][10]){
    int row,col;
    for (row=0;row<10;row++){
        for(col=0;col<10;col++){
            board1[row][col]=(char)247;
            board2[row][col]=(char)247;
        }
    }
}
int printBoard1(char board1[10][10],char board2[10][10]){
    int row,col;
    printf("             Player 1                            Player 2\n\n");
for(row=0;row<10;row++){
        printf("%c",(char)row+65);
        for(col=0;col<10;col++){
            printf("%3c",board1[row][col]);
        }
        printf("  |||");
        for(col=0;col<10;col++){
            printf("%3c",board2[row][col]);
        }
        printf("  %c",(char)row+65);
        printf("\n\n");
    }
    printf(" ");
    for(col=1;col<=10;col++){
        printf("%3d",col);
    }
    printf("     ");
    for(col=1;col<=10;col++){
        printf("%3d",col);
    }
    putchar('\n');


}
int setShip(char board1[10][10],char board2[10][10]){
    int i,j,choice;
    char row, direction[5];
    int col;


        printf("    #       ship         size");
        printf("\n[1] x1 Aircraft Carrier   5\n");
        printf("[2] x1 Battleship         4\n");
        printf("[3] x1 Cruiser            3\n");
        printf("[4] x2 Destroyer          2\n");
        printf("[5] x2 Cruiser            1\n\n");
        printf("Choose a ship:");
        scanf("%d",&choice);
        switch (choice){


            case 1:
                printf("-- Aircraft Carrier --\n");
                printf("Place Head(row,col): ");
                printf("row: ");
                scanf("%c",&row);
                getchar();
                printf("col: ");
                scanf("%d",&col);
            break;
            case 2:
            break;
            case 3:
            break;
            case 4:
            break;
            case 5:
            break;
            default:
            break;
        }
        printf("From head (up,down,left,right): ");
        scanf("%s", direction);
        printf("%s", direction);
        if(strcmp(direction,"up")==0){
            if (choice==1){
                for(i=0;i<5;i++){
                    board1[(int)row-65][col-1]= 'A';
                    row--;
                }
            }
            printBoard1(board1,board2);
        }
}
main(){
    char board1[10][10];
    char board2[10][10];
    printf("Hello! Welcome to Battleship C!\n");
    printf("What would you like to do?\n\n");
    if (main_menu(board1,board2)==0){
        return 0;
    }
}

my problem is in this function below

Code:

int setShip(char board1[10][10],char board2[10][10]){    int i,j,choice;
    char row, direction[5];
    int col;


        printf("    #       ship         size");
        printf("\n[1] x1 Aircraft Carrier   5\n");
        printf("[2] x1 Battleship         4\n");
        printf("[3] x1 Cruiser            3\n");
        printf("[4] x2 Destroyer          2\n");
        printf("[5] x2 Cruiser            1\n\n");
        printf("Choose a ship:");
        scanf("%d",&choice);
        switch (choice){


            case 1:
                printf("-- Aircraft Carrier --\n");
                printf("Place Head(row,col): ");
                printf("row: ");
                scanf("%c",&row);
                getchar();
                printf("col: ");
                scanf("%d",&col);
            break;
            case 2:
            break;
            case 3:
            break;
            case 4:
            break;
            case 5:
            break;
            default:
            break;
        }
        printf("From head (up,down,left,right): ");
        scanf("%s", direction);
        printf("%s", direction);
        if(strcmp(direction,"up")==0){
            if (choice==1){
                for(i=0;i<5;i++){
                    board1[(int)row-65][col-1]= 'A';
                    row--;
                }
            }
            printBoard1(board1,board2);
        }
}

then when i print it the values doesnt change to 'A'... why?
any help is appreciated

i cannot set the values to 'A' and print it..

**GReaper** · 02-18-2012

You don't even use your counter in the for loop, line #42.

EDIT: Never mind, I didn't see that you're decrementing "row".

EDIT^2: Wait, what is this?

Code:

board1[(int)row-65][col-1]= 'A';

"row-65"? Why?!

EDIT^3: Oh, it's a character. See, things get confusing when you replace well defined symbols( 'A') with magic numbers(65) ...

**Isnalla** · 02-18-2012

i want to set value 'A' from the user's initial input and to the 4 units above it

EDIT: sorry for no documentation... just started writing this today O_O.

**Isnalla** · 02-18-2012

Originally Posted by GReaper

You don't even use your counter in the for loop, line #42.

EDIT: Never mind, I didn't see that you're decrementing "row".

EDIT^2: Wait, what is this?

Code:

board1[(int)row-65][col-1]= 'A';

"row-65"? Why?!

because a standard battleship game has characters for row and integers for the column,
so when the user inputs J 5 it would be like 9 4 (J in ASCII is 74.. -65 it will be 9)..
i dont know if that logic is right O_O.. seems right to me.. please correct me if im wrong.

EDIT: then it would be like board1[9][4]='A'; and 4 units above it would be 'A' too. that's what i would want to do..

**Isnalla** · 02-18-2012

Originally Posted by GReaper

EDIT^3: Oh, it's a character. See, things get confusing when you replace well defined symbols( 'A') with magic numbers(65) ...

oh. so can i do something like this instead?

board1[(int)row-A][col-1]='A' ??

or board1[(int)row-(int)'A'][col-1]='A' ??

or neither... *sigh* i'm currently studying basic C
and i just learned typecasting the other day.. so
i guess i still have a lot to learn.

**GReaper** · 02-18-2012

You don't need a cast at all. The character is promoted to integer, behind the scenes, while your code retains its readability.

**Isnalla** · 02-18-2012

^ it compiled..

. but it still doesnt print those values.. can you see anything wrong? or should i add something ...

**GReaper** · 02-18-2012

Post your whole code please, a test-drive will reveal the root of the problem.

**Isnalla** · 02-18-2012

just removed the typecast at the setShip function. i hope i did right

Code:

#include <stdio.h>#include <stdlib.h>
#include <string.h>


int main_menu(char board1[10][10],char board2[10][10]){
    int choice;
    printf(" \n_____________\n");
    printf("|--Main Menu--|\n");
    printf("|             |\n");
	printf("|[1]Game Start|\n");            //print main menu
	printf("|[2]Logout    |\n");
    printf(" ~~~~~~~~~~~~~\n\n");


    do{
        printf("Enter Choice: ");
        scanf("%d",&choice);
        if (choice==2) {
            return 0;
        }
        else if (choice!=1){
            printf("Choice invalid!\n");
        }
    }while(choice!=2 && choice!=1);
    do{
    printf("\n[1]Single Player\n");
    printf("[2]Multiplayer\n");
    printf("[3]Go back\n");
    scanf("%d", &choice);
       switch(choice){
            case 1:
                setBoard1(board1,board2);
                printBoard1(board1,board2);
                setShip(board1,board2);
                break;
            case 2:
                return 0;
                break;
            case 3:
                main_menu(board1,board2);
                break;
            default:printf("Choice invalid!");
                break;
       }
    }while(choice!=3);
}


int setBoard1(char board1[10][10], char board2[10][10]){
    int row,col;
    for (row=0;row<10;row++){
        for(col=0;col<10;col++){
            board1[row][col]=(char)247;
            board2[row][col]=(char)247;
        }
    }
}
int printBoard1(char board1[10][10],char board2[10][10]){
    int row,col;
    printf("             Player 1                            Player 2\n\n");
for(row=0;row<10;row++){
        printf("%c",(char)row+65);
        for(col=0;col<10;col++){
            printf("%3c",board1[row][col]);
        }
        printf("  |||");
        for(col=0;col<10;col++){
            printf("%3c",board2[row][col]);
        }
        printf("  %c",(char)row+65);
        printf("\n\n");
    }
    printf(" ");
    for(col=1;col<=10;col++){
        printf("%3d",col);
    }
    printf("     ");
    for(col=1;col<=10;col++){
        printf("%3d",col);
    }
    putchar('\n');


}
int setShip(char board1[10][10],char board2[10][10]){
    int i,j,choice;
    char row, direction[5];
    int col;


        printf("    #       ship         size");
        printf("\n[1] x1 Aircraft Carrier   5\n");
        printf("[2] x1 Battleship         4\n");
        printf("[3] x1 Cruiser            3\n");
        printf("[4] x2 Destroyer          2\n");
        printf("[5] x2 Cruiser            1\n\n");
        printf("Choose a ship:");
        scanf("%d",&choice);
        switch (choice){


            case 1:
                printf("-- Aircraft Carrier --\n");
                printf("Place Head(row,col): ");
                printf("row: ");
                scanf("%c",&row);
                getchar();
                printf("col: ");
                scanf("%d",&col);
            break;
            case 2:
            break;
            case 3:
            break;
            case 4:
            break;
            case 5:
            break;
            default:
            break;
        }
        printf("From head (up,down,left,right): ");
        scanf("%s", direction);
        printf("%s", direction);
        if(strcmp(direction,"up")==0){
            if (choice==1){
                for(i=0;i<5;i++){
                    board1[row-'A'][col-1]= 'A';
                    row--;
                }
            }
            printBoard1(board1,board2);
        }
}
main(){
    char board1[10][10];
    char board2[10][10];
    printf("Hello! Welcome to Battleship C!\n");
    printf("What would you like to do?\n\n");
    if (main_menu(board1,board2)==0){
        return 0;
    }
}

**GReaper** · 02-19-2012

I got it. You set the board every single time. Set the board only once. That should fix your problem.

EDIT: Note that you firstly print the board and then you update it by calling "setShip()". That combined with the fact that you set the board to default values every time, produces this result.

**Isnalla** · 02-19-2012

i got it! did that ^ then put a getchar(); (on line95)below scanf("%d", &choice); (line 94)

seems like the "enter" character goes to scanf("%c",&row);(line 102) when i input the choice.. >.<

**Isnalla** · 02-19-2012

many thanks!

**Adak** · 02-19-2012

Having the newline char mess up a char scanf() is one of the most common complaints we see on the forum.

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