https://code.google.com/codejam/contest/9214486/dashboard

io_error.c

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

int main() {
    int nbytes, ncases, i, j, k;
    char c, res;
    char ** msgs;

    scanf("%d", &ncases);
    msgs = malloc(ncases * sizeof(char *));

    for (i = 0; i < ncases; i++) {
        scanf("%d", &nbytes);
        msgs[i] = malloc(nbytes+1);
        for (j = 0; j < nbytes; j++) {
            res = 0;
            for (k = 0; k < 8; k++) {
                scanf(" %c", &c);
                if (c == 'O') 
                    res = res << 1;
                else if (c == 'I')
                    res = (res << 1) | 1;
            }
            msgs[i][j] = res;
        }
        msgs[i][nbytes+1] = '\0';
    }

    for (i = 0; i < ncases; i++) {
        printf("Case #%d: %s", i, msgs[i]);
        printf("\n");
    }
    return 0;
}