Beautiful String.cpp

int n = str.size();

 

    int count1 = 0, count2 = 0;

 

 

 

    // Count the number of operations needed to change the string to '010101...'

 

    for (int i = 0; i < n; ++i) {

 

        if (i % 2 == 0 && str[i] != '0') {

 

            count1++;

 

        }

 

        if (i % 2 == 1 && str[i] != '1') {

 

            count1++;

 

        }

 

    }

 

 

 

    // Count the number of operations needed to change the string to '101010...'

 

    for (int i = 0; i < n; ++i) {

 

        if (i % 2 == 0 && str[i] != '1') {

 

            count2++;

 

        }

 

        if (i % 2 == 1 && str[i] != '0') {

 

            count2++;

 

        }

 

    }

 

 

 

    // Return the minimum of the two counts

 

    return min(count1, count2);