UVA673- Parentheses Balance

題意：匹配括弧

思路：利用STL中的stack做的，記住Null 字元串也是Yes。

#include<iostream>#include<cstdio>#include<cstring>#include<stack>#include<algorithm>using namespace std;int main() {int n;char s[150];scanf("%d", &n);getchar();while (n--) {stack <char> str;gets(s);for(int i = 0; i < strlen(s); i++) {if (s[i] == '(' || s[i] == '[')str.push(s[i]);else if (s[i] == ')' || s[i] == ']') {if (s[i] == ')' && !str.empty()) {if (str.top() == '(')str.pop();}else if (!str.empty() && s[i] == ']') {if (str.top() == '[')str.pop();}else str.push(s[i]);}}if (str.empty())printf("Yes\n");else printf("No\n");}return 0;}