How to convert string to integer and integer to string in c++

C++ programm

#include <cmath>
#include <cstdio>
#include <vector>
#include <string> 
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    
    int a,b,c,val,co=0;
    string s,revs;
    cin>>a>>b>>c;
    for(int i=min(a,b);i<=max(a,b);i++){
        s= to_string(i);
        reverse(s.begin(), s.end()); 
        val=atoi(s.c_str());
        if(abs(i-val)%c==0)
            co++;
      }
    cout<<co;
      
    return 0;
}