/** \file Valid Parentheses.cpp
  * \details
  *     Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.
  *     The brackets must close in the correct order, "()" and "()[]{}" are all valid but "(]" and "([)]" are not.
  * \author LOC
  */

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

//! \brief check string is valid? return true if valid otherwise false
//! \param string[] a string which entered from keyboard
//! \return true if valid and false if invalid
bool Solution(char string[]){
    int length = strlen(string);
    for(int i=0; i<length; i+=2){
        if((string[i]=='[' && string[i+1]==']') || (string[i]=='{' && string[i+1]=='}') || (string[i]=='(' && string[i+1]==')') )
            return true;
    else return false;
    }
}

int main(){
    char string[10];
    cout < "Enter a string";
    cin.getline(string,10);
    if (Solution(string)) cout << "Your string is valid";
    else cout << "Your string is invalid";
    return 0;
}

leetcode.com

Valid Parentheses

C++