arc 092C 2D Plane 2N Points

 1 #include <stdio.h>
 2 #include <string.h>
 3 
 4 const int N = 105;
 5 
 6 int link[N];
 7 bool mp[N][N];
 8 bool vis[N];
 9 
10 struct node
11 {
12     int x,y;
13 } red[N],blue[N];
14 
15 bool dfs(int u,int n)
16 {
17     for (int i = 0;i < n;i++)
18     {
19         if (mp[u][i] && !vis[i])
20         {
21             vis[i] = 1;
22             
23             if (link[i] == -1 || dfs(link[i],n))
24             {
25                 link[i] = u;
26                 return true;
27             }
28         }
29     }
30     
31     return false;
32 }
33 
34 int solve(int n)
35 {
36     int ans = 0;
37     
38     for (int i = 0;i < n;i++)
39     {
40         memset(vis,0,sizeof(vis));
41         if (dfs(i,n)) ans++;
42     }
43     
44     return ans;
45 }
46 
47 int main()
48 {
49     int n;
50     
51     scanf("%d",&n);
52     
53     memset(link,-1,sizeof(link));
54     
55     for (int i = 0;i < n;i++)
56     {
57         scanf("%d%d",&red[i].x,&red[i].y);
58     }
59     
60     for (int i = 0;i < n;i++)
61     {
62         scanf("%d%d",&blue[i].x,&blue[i].y);
63     }
64     
65     for (int i = 0;i < n;i++)
66     {
67         for (int j = 0;j < n;j++)
68         {
69             if (red[i].x < blue[j].x && red[i].y < blue[j].y)
70             {
71                 mp[i][j] = 1;
72             }
73         }
74     }
75     
76     int ans = solve(n);
77     
78     printf("%d\n",ans);
79     
80     return 0;
81 }