What am i doing wrong in this loop-CodePudding

#include <stdio.h>
#define ROWS 2
#define COLS 5

int main(void)
{
    unsigned int rooms[ROWS][COLS] = {0}, selection, building, room;
    int i, j;
    for(i = 0; i < ROWS; i  )
    {
        for(j = 0; j < COLS; j  )
        {
            if(rooms[i][j] == 0)
            {
                rooms[i][j] = 1;
                printf("\nBuilding[%.2d]|Room[%.2d]: Reservation Succesfull.\n\n", i   1, j   1);
                break;
            }
        }
    }
    return 0;
}

Note that this is not the full code and i only have a problem with this part.

What i want here is to check the first 0 that comes first and turn it into a 1. This will happen until all the 0 become 1 or until the user exits the program. I already made a "do while" for that. My problem is that when i run this part of the program it puts 1 both on ROWS 0 and ROWS 1 at the same time. I'm looking for why is this happening more than an answer to fix the program.

I made some tests like putting another if for the first loop(i) but that either resulted in the same problem or the whole ROWS 1 was skipped and only the ROWS 0 was filled.

CodePudding user response：

It is because the break statement just gets out of the first outer loop, it seems like you also want to skip the other outer one. You may need to add a flag to check only one 0 element will be changed to 1, or just change break into return to get out of the function as it is said on the comments.

    int flag = 0;
    for(i = 0; i < ROWS; i  )
    {
        for(j = 0; j < COLS; j  )
        {
            if(rooms[i][j] == 0)
            {
                flag = 1;
                rooms[i][j] = 1;
                printf("\nBuilding[%.2d]|Room[%.2d]: Reservation Succesfull.\n\n", i   1, j   1);
                break;
            }
        }
        if(flag == 1)
        {
            break;
        }
    }

Or with a clear explicit initialization of the matrix,

void func(void)
{
    unsigned int rooms[ROWS][COLS] = {
        {0, 0, 0, 0, 0},
        {0, 0, 0, 0, 0}
    }, selection, building, room;
    int i, j;
    for(i = 0; i < ROWS; i  )
    {
        for(j = 0; j < COLS; j  )
        {
            if(rooms[i][j] == 0)
            {
                rooms[i][j] = 1;
                printf("\nBuilding[%.2d]|Room[%.2d]: Reservation Succesfull.\n\n", i   1, j   1);
                return;
            }
        }
    }
}