Find Duplicate in Range 0 and n-1

#include <stdio.h>

int find_duplicate(int arr[], int n) {

    int temp[100] = {0};

    for(int i = 0; i < n; i++){
        temp[arr[i]]++;
    }

    int largest = temp[0];
    int index = 0;

    for(int i = 1; i < 100; i++){
        if(temp[i] > largest){
            largest = temp[i];
            index = i;
        }
    }

    return index;
}

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;
}