Number of substrings of one string present in other

Given 2 strings A and B, the task is to count the number of substrings of A which are also present in B.

Example:

Input: a="plu" b="Cplusplus" 
Output: 6 

Explanation: 
p, l, u, pl, lu, and plu are the 6 substrings of string a present in string b also.

Approach:
We will just run 2 loops and find every substring of string a and check if it’s present in string b or not.

Implementation in C++:

#include <bits/stdc++.h> 
using namespace std; 

int count(string a, string b)
{
	int count=0;
	int n=a.size();
	
	for(int i=1;i<=n;i++)
	{
	    for(int j=0;j<=n-i;j++)
	    {
	        string str=a.substr(j,i);
	        
	        int pos=b.find(str);
	        if(pos!=-1)
	            count++;
	           
	    }
	}
	return count;
}

int main()
{
	string a="plu", b="Cplusplus";
	cout<<count(a,b);
	return 0;
}

Output:

6

Time Complexity: O(n*n) = O(n^2)