Parentheses Balance（673）

You are given a string consisting of parentheses () and []. A string of this type is said to be correct:

(a)

if it is the empty string

(b)

if A and B are correct, AB is correct,

(c)

if A is correct, (A ) and [A ] is correct.

Write a program that takes a sequence of strings of this type and check their correctness. Your program can assume that the maximum string length is 128.

Input 

The file contains a positive integer n and a sequence of n strings of parentheses () and [], one string a line.

Output 

A sequence of Yes or No on the output file.

Sample Input 

3([])(([()])))([()[]()])()

Sample Output 

YesNo
Yes
注：用堆栈，是(,[就入栈，),]就出栈
#include <cstdio>#include <cstring>#include <cmath>#include <cstdlib>#include <cctype>#include <iostream>#include <algorithm>#include <vector>#include <stack>#include <deque>#include <queue>#include <set>#include <list> #include <map> #include <string>using namespace std; #define infinity 2147483647int gcd(int a,int b){return b==0?a:gcd(b,a%b);}int main(){int n,i,l,flag;char s[1000];stack<char>ss;while(scanf("%d",&n)!=EOF){getchar();while(n--){gets(s);while(!ss.empty()){ss.pop();}flag=1;l=strlen(s);for(i=0;i<l;i++){if(s[i]=='(' || s[i]=='[')ss.push(s[i]);else if(s[i]==')'){if(ss.empty()){flag=0;break;}else if(ss.top()=='(')ss.pop();else{flag=0;break;}}else if(s[i]==']'){if(ss.empty()){flag=0;break;}else if(ss.top()=='[')ss.pop();else{flag=0;break;}}}if(flag && ss.empty())cout <<"Yes" <<endl;elsecout <<"No" <<endl;}}return 0;}