Find Duplicate in Range 0 and n-1

Code

#include <stdio.h>


int find_duplicate(int arr[], int n) {
    // Your logic here
    int temp=0;
    //sorted
    for (int i=0;i<n;i++){
        for (int j=0;j<n;j++){
            if (arr[i]>arr[j]){
                temp=arr[j];
                arr[j]=arr[i];
                arr[i]=temp;
            }

        }
    }
    for (int i=0;i<n-1;i++){
        if (arr[i+1]==arr[i]){
            return arr[i];
        }
    }
    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;
}

Solving Approach