hdu 6299 Balanced Sequence( 2018 Multi-University Training Contest 1 )

Posted 2020-12-25 jaydenouyang

 1 #include <stdio.h>
 2 #include <iostream>
 3 #include <cstdlib>
 4 #include <cmath>
 5 #include <string>
 6 #include <cstring>
 7 #include <algorithm>
 8 #include <stack>
 9 #include <queue>
10 #include <set>
11 #include <map>
12 #include <vector>
13 using namespace std;
14 typedef long long ll;
15 typedef unsigned long long ull;
16 
17 #define Faster ios::sync_with_stdio(false),cin.tie(0)
18 #define Read freopen("in.txt", "r", stdin),freopen("out.txt", "w", stdout)
19 const int INF = 0x3f3f3f3f;
20 const int maxn = 1e5 + 5;
21 const int MOD = 1e9 + 7;
22 
23 struct node{
24     int left, right;
25     bool operator < (const node& x) const {
26         if(left <= right && x.right < x.left) return false;
27         else if(left > right && x.right >= x.left) return true;
28         if(left <= right && x.right >= x.left) return left > x.left;
29         else return right < x.right;
30     }
31 }a[maxn];
32 
33 int main() 
34 {
35     Faster;
36     int t;
37     cin >> t;
38     while(t--){
39         int n;
40         cin >> n;
41         int ans = 0;
42         for(int i = 0;i < n;i++){
43             string s;
44             cin >> s;
45             a[i].left = a[i].right = 0;
46             for(int j = 0;j < s.size();j++){
47                 if(s[j] == ‘(‘){
48                     a[i].left++;
49                 }
50                 else if(s[j] == ‘)‘){
51                     if(a[i].left > 0){
52                         a[i].left--;
53                         ans += 2;
54                     }
55                     else{
56                         a[i].right++;
57                     }
58                 }
59             }
60         }
61         sort(a, a+n);
62         int now = 0;    //记录有多少左括号没有匹配
63         for(int i = 0;i < n;i++){
64             if(a[i].right > now)
65                 a[i].right = now;
66             ans += a[i].right*2;
67             now -= a[i].right;
68             now += a[i].left;
69         }
70         cout << ans << endl;
71     }    
72     return 0;
73 }