chall.c

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

int main(int argc, char **argv)
{
    int c[] = {119, 74, 101, 91, 107, 81, 116, 44, 16, 99, 20, 107, 76, 41, 127, 122, 20, 118, 71, 71, 80, 125, 82, 117, 17, 118, 84, 44, 20, 118, 127, 44, 84, 44, 83, 44, 78, 71, 78, 43, 87, 122, 73, 43, 127, 126, 82, 113, 69, 118, 68, 116, 89, 101};
    char inp[100];
    printf("apa flagnya\n");
    scanf("%s", &inp);
    int len = strlen(inp);
    if (len != 54)
    {
        printf("bukan");
        return 0;
    }
    for (int i = 0; i < len; i++)
    {
        if (i % 2 == 1 && inp[i] != (c[i] ^ 24))
        {
            printf("bukan");
            return 0;
        }
        else if (i % 2 == 0 && inp[i] != (c[i] ^ 32))
        {
            printf("bukan");
            return 0;
        }
    }
    printf("mantap!!\n");
    return 0;
}