uva673-Parentheses Balance
Parentheses Balance |
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
Yes No Yes
这是一道模拟题,注意空行的处理就可以
#include <iostream>
#include <stack>
#include <string>
#include <map>
using namespace std;
map<char, char> m;
stack<char> st1;
int main(void){
string s;
int num;
int flag;
#ifndef ONLINE_JUDGE
freopen("f:\\infile.txt", "r", stdin);
#endif
m['('] = ')';
m['['] = ']';
cin >> num;
cin.ignore(10, '\n');
while(num--){
getline(cin, s);
flag = 0;
while(st1.size())
st1.pop();
for(int i = 0; i < s.size(); i++){
if((s[i] == '(') || (s[i] == '['))
st1.push(s[i]);
else if(st1.size() && (s[i] == m[st1.top()])){
st1.pop();
}
else{
flag = 1;
break;
}
}
if(flag == 1){
cout << "No" << endl;
continue;
}
if(!st1.size())
cout << "Yes";
else
cout << "No";
// if(num != 0)
cout << endl;
}
return 0;
}