hdu 2255 奔小康赚大钱 (KM)

 1 #include <map>
 2 #include <queue>
 3 #include <cmath>
 4 #include <vector>
 5 #include <string>
 6 #include <cstdio>
 7 #include <cstring>
 8 #include <climits>
 9 #include <iostream>
10 #include <algorithm>
11 #define INF 0x3f3f3f3f
12 using namespace std;
13 const int my_max = 310;
14 
15 int n, nx, ny, my_map[my_max][my_max], my_lx[my_max], my_line[my_max],
16     my_slack[my_max], my_bookx[my_max], my_booky[my_max], my_ly[my_max];
17 
18 bool my_dfs(int x)
19 {
20     my_bookx[x] = 1;
21     for (int i = 1; i <= ny; ++ i)
22     {
23         if (my_booky[i]) continue;
24         int temp = my_lx[x] + my_ly[i] - my_map[x][i];
25         if (temp == 0)
26         {
27             my_booky[i] = 1;
28             if (!my_line[i] || my_dfs(my_line[i]))
29             {
30                 my_line[i] = x;
31                 return true;
32             }
33         }
34         else if (my_slack[i] > temp)
35             my_slack[i] = temp;
36     }
37     return false;
38 }
39 
40 int my_km()
41 {
42     memset(my_lx, 0, sizeof(my_lx));
43     memset(my_line, 0, sizeof(my_line));
44 
45     for (int i = 1; i <= nx; ++ i)
46         for (int j = 1; j <= ny; ++ j)
47             if (my_map[i][j] > my_lx[i])
48                 my_lx[i] = my_map[i][j];
49 
50     for (int i = 1; i <= nx; ++ i)
51     {
52         for (int j = 1; j <= ny; ++ j)
53             my_slack[j] = INF;
54         while (1)
55         {
56             memset(my_bookx, 0, sizeof(my_bookx));
57             memset(my_booky, 0, sizeof(my_booky));
58 
59             if (my_dfs(i)) break;
60 
61             int my_temp_min = INF;
62             for (int j = 1; j <= ny; ++ j)
63                 if (!my_booky[j] && my_slack[j] < my_temp_min)
64                     my_temp_min = my_slack[j];
65 
66             for (int j = 1; j <= nx; ++ j)
67                 if (my_bookx[j]) my_lx[j] -= my_temp_min;
68             for (int j = 1; j <= ny; ++ j)
69                 if (my_booky[j]) my_ly[j] += my_temp_min;
70                 else my_slack[j] -= my_temp_min;
71         }
72     }
73     int my_ans = 0;
74     for (int i = 1; i <= ny; ++ i)
75         my_ans += my_map[my_line[i]][i];
76     return my_ans;
77 }
78 
79 int main()
80 {
81     while (~scanf("%d", &n))
82     {
83         nx = ny = n;
84         for (int i = 1; i <= n; ++ i)
85             for (int j = 1; j <= n; ++ j)
86                 scanf("%d", &my_map[i][j]);
87         printf("%d\n", my_km());
88     }
89     return 0;
90 }