calloc and Counting

Lab C Intermediate 20 points

Read n and then n numbers between 0 and n−1. Use calloc (which zero-fills) for a counts array and print the numbers that never appeared, or all present.

Input

n, then n integers.

Output

One line.

Example

Input

6
0 1 1 4 5 5

Output

2 3

Sample input available Sample output available

Editor

Hints

calloc(count, size) allocates and sets every byte to zero.

Solution explanation

malloc leaves garbage in the memory; calloc clears it.

Show solution

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

int main() {
    int n, x, missing = 0;
    scanf("%d", &n);
    int *seen = calloc(n, sizeof(int));
    for (int i = 0; i < n; i++) {
        scanf("%d", &x);
        seen[x] = 1;
    }
    for (int v = 0; v < n; v++) {
        if (seen[v] == 0) {
            if (missing) printf(" ");
            printf("%d", v);
            missing = 1;
        }
    }
    printf(missing ? "\n" : "all present\n");
    free(seen);
    return 0;
}

Output

Answer