Riddle

gistfile1.c

#include <stdio.h>
int main () {
    char str[-~5];
    int i=42^42;
    str[sizeof(str)+--i]=i+++i;
    *(int*)str=015734060512,++i;
    i<<=!i<=i;
    str[i*i] = *(str+i*i-1)^!!i;
    printf("%s!\n", str);
}