Matching Brackets - Easy Problems - Solution to Toph.co Online Judge Problem

Matching Brackets

Limits 1s, 512 MB

You will be given a sequence of opening and closing brackets of different types ((, ), [, ], {, and }). You will have to determine if the sequence is a valid one.

A sequence of brackets is considered valid if every opened bracket of a type has a closing bracket of an equivalent type appearing after it. And, there are no unpaired brackets in the sequence.

Input

The input will contain a string of opening and closing brackets. The string will be no longer than 25 characters.

Output

Print “Yes” if the input string contains a valid sequence of parentheses. Otherwise, print “No”.

Samples

Input	Output
[[(){]}]	No

Input	Output
(([]{}[{}]){})[]	Yes

Solution:

#include <bits/stdc++.h> using namespace std; int main() { string s; stack<char> a; cin>>s; for(int i=0;i<s.length();i++) { if(s[i] == '(' || s[i] == '{' || s[i] == '[') a.push(s[i]); else { if(a.empty()) { cout<<"No"<<endl; return 0; } else if(s[i] == ')') { if(a.top() == '(') { a.pop(); } } else if(s[i] == '}') { if(a.top() == '{') { a.pop(); } } else if(s[i] == ']') { if(a.top() == '[') { a.pop(); } } } } if(a.empty()) { cout<<"Yes"<<endl; return 0; } else cout<<"No"<<endl; }