Find Duplicate in Range 0 and n-1

#include <stdio.h>

int find_duplicate(int arr[], int n) {
    // Your logic here
    for(int i = 0; i < n; i++) {
        for(int x = i + 1; x < n; x++){
            if(arr[i] == arr[x]) {
                return arr[x];
            }
        }
    }

    return -1;
}

int main() {
    int n;
    scanf("%d", &n);

    int arr[100];
    for (int i = 0; i < n; i++) scanf("%d", &arr[i]);

    int result = find_duplicate(arr, n);
    printf("%d", result);
    return 0;
}