substring-problem

#include<iostream>
#include<cstdio>
#include<string>
#include<sstream>
#include<cstdlib>
using namespace std;
 
string str;
int main()
{
    int cases;
    cin >> cases;
    for(int t=0;t<cases;t++)
    {
        int n,k,result=0;
        cin >> n;
        cin >> k;
        stringstream ss;
        ss << k;
        string target = ss.str();
        for(int i=1;i<=n;i++)
        {
            char intStr[10];
            sprintf(intStr,"%d",i);
            str.append(string(intStr));         
        }
        if(target.length()>str.length())
        {
            result = 0;
        }
        else{
        for(int i=0;i<=str.length()-target.length();i++)
        {
            string temp = str.substr(i,target.length());
            int found = temp.find(target);
            if(found!=string::npos)
            {
                result++;
            }
        }
        }
        
        cout << result << endl;
        str.clear();        
    }
}