Codeforces Solution-B. Regular Bracket Sequence-Solution in C, C++, Java, Python

(()))(

4

((()())

6

#1 Code Example with C++ Programming

Code - C++ Programming

#include <cstdio>
#include <iostream>


int main(){

    std::string input; getline(std::cin, input);

    long unmatched(0), matched(0);

    for(int k = 0; k < input.size(); k++){
        if(input[k] == '('){++unmatched;}
        else if(input[k] == ')' && unmatched > 0){--unmatched; ++matched;}
    }

    std::cout << 2 * matched << std::endl;

    return 0;
}

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