Find Duplicate in Range 0 and n-1

Code

#include <stdio.h>


int find_duplicate(int arr[], int n) {
    // Your logic here
    int i, j, hit;
    for (i=0, hit=0; (i < n) && (hit == 0); i++) {
        for (j=i+1; j < n; j++) {
            if (arr[i] == arr[j]) {
                hit = 1;
                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

starting from top, look for a match in the elements below,

while not found you move down and look for a match in the lower elements only