Which solution do you think is the most efficient? And how to tell it?

/*https://www.geeksforgeeks.org/smallest-element-repeated-exactly-k-times-not-limited-small-range/
Smallest element repeated exactly ‘k’ times (not limited to small range)
*/
#include<bits/stdc++.h>
using namespace std;
int no_of_chars = 10;
int smallrepeat(int s[],int k, int n)
{
	int hash[no_of_chars] = {0};
	//Storing the frequency of occurances.
	for(int i=0;i<n;i++)
		hash[s[i]]++;
	//Finding smallest element repeated exactly 'k' times
	int repeatmore = 9;
	for(int i=0;i<n;i++){
		if(hash[s[i]] && (hash[s[i]] == k) && (s[i] < repeatmore))
			repeatmore = s[i];
	}

	return repeatmore;

}
int main()
{
	int s[] = { 2, 2, 1, 3, 1 };
	int n = sizeof(s)/sizeof(s[0]);
	int k = 2;
	cout<<"Smallest element repeated exactly ‘k’ times :"<<smallrepeat(s,k,n)<<endl;
}