Removing Triple Successive Duplicates - Google Top Interview Questions


Problem Statement :


Given a string s containing "0"s and "1"s, consider an operation where you pick a character and toggle its value from "0" to "1" or from "1" to "0". Return the minimum number of operations required to obtain a string containing no instances of three identical consecutive characters.

Constraints

0 ≤ n ≤ 100,000 where n is the length of s


Example 1

Input

s = "1100011"

Output

1

Explanation

We can toggle the middle "0" to a "1".



Example 2

Input

s = "0001000"

Output

2

Explanation

We can toggle the first and the last characters to get "1001001"


Solution :



title-img 




                        Solution in C++ :

int solve(string s) {
    int ret = 0;
    for (int i = 0; i < s.size();) {
        int j = i + 1;
        while (j < s.size() && s[i] == s[j]) {
            j++;
        }
        ret += (j - i) / 3;
        i = j;
    }
    return ret;
}
                    


                        Solution in Java :

import java.util.*;

class Solution {
    public int solve(String s) {
        int len = s.length();
        int k = 0;
        for (int i = 0; i < len - 2;) {
            if (s.charAt(i) == s.charAt(i + 1) && s.charAt(i) == s.charAt(i + 2)) {
                k++;
                i += 2;
            }
            i++;
        }
        return k;
    }
}
                    


                        Solution in Python : 
                            
class Solution:
    def solve(self, s):
        return s.count("000") + s.count("111")


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