#include <iostream>
int element_exist(int arr[], int len, int start, int n) {
for (int i = start; i <= len; i++) {
if (arr[i] == n)
return 1;
}
return 0;
}
int get_first_repeating_element(int arr[], int len) {
for (int i = 0; i <= len; i++) {
if (element_exist(arr, len, i + 1, arr[i]))
return arr[i];
}
return -1;
}
int main()
{
int arr[] = {1, 2, 4, 5, 6, 5, 4, 3, 7};
int n = get_first_repeating_element(arr, sizeof(arr) / sizeof(arr[0]));
if (n != -1)
std::cout << "First repeating element is: " << n;
else
std::cout << "No repeating elements";
}
/*
run:
First repeating element is: 4
*/