In this practicle i am unable to find values in one and two

Question

#include <iostream>
using namespace std;
#include <string>

int main()
{
string num;
cin>>num;

string b;
cout <<" enter number";

cin >> b;

int a;
cout << "enter index";

cin >> a;

int cnt = int(b.length());
int index = num.find(b);

string one="", two="";

for(int i = index; i < index + cnt; i++)
{
num[i] =' ';
}
for(int i = 0; i < a; i++)
{
one[i] = num[i];
}
for(int i = a; i < int(num.length()); i++)
{
two[i - a] = num[i];
}

string new1 = ""+ one + b + two;
cout << num;

}

Answer 1

Not getting the flow. Can you describe or illustrate what the code should actually do?