NYOJ 16 矩形嵌套（经典DP）

 1 #include<iostream> 
 2 #include<algorithm>
 3 using namespace std;
 4 
 5 const int maxn = 1000+5;
 6 
 7 int n;
 8 int dp[maxn];
 9 
10 struct node
11 {
12     int a, b;
13 }a[maxn];
14 
15 bool cmp(node x, node y)
16 {
17     if (x.a == y.a)    return x.b < y.b;
18     return x.a < y.a;
19 }
20 
21 int main()
22 {
23     //freopen("D:\\txt.txt", "r", stdin);
24     int t;
25     cin >> t;
26     while (t--)
27     {
28         cin >> n;
29         for (int i = 0; i < n; i++)
30         {
31             cin >> a[i].a >> a[i].b;
32             if (a[i].a < a[i].b)
33             {
34                 int temp = a[i].b;
35                 a[i].b = a[i].a;
36                 a[i].a = temp;
37             }
38         }
39         sort(a, a + n, cmp);
40         int _Max = 0;
41         for (int i = 0; i < n; i++)
42         {
43             dp[i] = 1;
44             for (int j = 0; j < i; j++)
45             {
46                 if (a[j].a < a[i].a && a[j].b < a[i].b)
47                 {
48                     dp[i] = max(dp[i], dp[j] + 1);
49                 }
50             }
51             if (dp[i]>_Max)  _Max = dp[i];
52         }
53         cout << _Max << endl;
54     }        
55     return 0;
56 }