Minimum steps to remove substring 010 from a binary string in C++

Problem statement

Given a binary string, the task is to count the minimum steps to remove substring 010 from this binary string

Example

If input string is 010010 then 2 steps are required

• Convert first 0 to 1. Now string becomes 110010
• Convert last 0 to 1. Now final string becomes 110011

Algorithm

1. Iterate the string from index 0 sto n-2
2. If in binary string has consecutive three characters ‘0’, ‘1’, ‘0’ then any one character can be changed
Increase the loop counter by 2

Example

 Live Demo

#include <bits/stdc++.h>
using namespace std;
int getMinSteps(string str) { 
   int cnt = 0;
   for (int i = 0; i < str.length() - 2; ++i) {
      if (str[i] == '0' && str[i + 1] == '1' && str[i+ 2] == '0') {
         ++cnt;
         i += 2;
      }
   }
   return cnt;
}
int main() {
   string str = "010010";
   cout << "Minimum required steps = " << getMinSteps(str)
   << endl;
   return 0;
}

When you compile and execute above program. It generates following output

Output

Minimum required steps = 2