From 1...n in an array, find missing integers

count.c

#include <stdio.h>

int main()
{
    int size;
    printf("size: ");
    scanf("%d", &size);

    int arr[size];
    for(int i = 0; i < size; i++)
    {
        printf("[%d]: ", i);
        scanf("%d", (arr+i));
    }

    // Get largest to look for n in [1..n]
    int largest = *arr;
    for(int i = 0; i < size; i++)
    {
        if(*(arr+i) > largest) largest = *(arr+i);
    }

    // Look for missing
    int miss[size];
    int missCtr = 0;
    
    for(int ctr = 1; ctr <= largest; ctr++)
    {
        int found = 0;      
        for(int iter = 0; iter < size; iter++)
        {
            if(*(arr+iter) == ctr)
            {
                found = 1;
                break;
            } 
        }
        if(!found) {
            *(miss+missCtr) = ctr;
            missCtr++;
        }
    }

    printf("Missing: ");
    for(int i = 0; i < missCtr; i++)
    {
        printf("%d ", *(miss+i));
    }

    return 0;
}