二分图最小权值匹配KM算法~

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1 #include <stdio.h>
 2 #include <string.h>
 3 #include <stdlib.h>
 4 #include <math.h>
 5 #include <assert.h>
 6 #include <ctype.h>
 7 #include <map>
 8 #include <string>
 9 #include <set>
 10 #include <bitset>
 11 #include <utility>
 12 #include <algorithm>
 13 #include <vector>
 14 #include <stack>
 15 #include <queue>
 16 #include <iostream>
 17 #include <fstream>
 18 #include <list>
 19
20 usingnamespace std;
 21
22 constint MAXN =128;
 23 constint INF =1000000000;
 24
25 int N;
 26 int g[MAXN][MAXN];
 27 int pre[MAXN];
 28 int lx[MAXN], ly[MAXN], slack[MAXN];
 29 bool visx[MAXN], visy[MAXN];
 30
31 int data[MAXN][MAXN];
 32
33 void BuildGraph()
 34 {
 35 int i, j, k, nr, nc;
 36
37 scanf("%d %d",&nc,&nr);
 38 for (i =0;i < nr;i++)
 39 for (j =0;j < nc;j++)
 40 scanf("%d",&data[i][j]);
 41
42 N = nc;
 43
44 for (i =0; i < N; i++)
 45 for (j =0; j < N; j++)
 46 {
 47 int sum =0;
 48 for (k =0;k < nr;k++)
 49 sum += abs(i+1-data[k][j]);
 50 g[i][j] =-sum;
 51 }
 52 }
 53
54 bool dfs(int t)
 55 {
 56 int i;
 57 visx[t] =true;
 58 for (i =0; i < N; i++)
 59 {
 60 if (visy[i]) continue;
 61 int tmp = lx[t]+ly[i]-g[t][i];
 62 if (tmp ==0)
 63 {
 64 visy[i] =true;
 65 if (pre[i] ==-1|| dfs(pre[i]))
 66 {
 67 pre[i] = t;
 68 returntrue;
 69 }
 70 }
 71 elseif (slack[i] > tmp)
 72 {
 73 slack[i] = tmp;
 74 }
 75 }
 76 returnfalse;
 77 }
 78 int KM()
 79 {
 80 int i, j;
 81 memset(pre, -1, sizeof(pre));
 82 memset(ly, 0, sizeof(ly));
 83 for(i =0; i < N; i++)
 84 lx[i] =-INF;
 85 for(i =0; i < N; i++)
 86 {
 87 for(j =0; j < N; j++)
 88 {
 89 if(lx[i] < g[i][j])
 90 lx[i] = g[i][j];
 91 }
 92 }
 93 for(i =0; i < N; i++)
 94 {
 95 for(j =0; j < N; j++)
 96 slack[j] = INF;
 97 while(1)
 98 {
 99 memset(visx, false, sizeof(visx));
100 memset(visy, false, sizeof(visy));
101 if(dfs(i)) break;
102 int d = INF;
103 for(j =0; j < N; j++)
104 if(!visy[j] && slack[j] < d)
105 d = slack[j];
106 for(j =0; j < N; j++)
107 if(visx[j]) lx[j] -= d;
108 for(j =0; j < N; j++)
109 {
110 if(visy[j]) ly[j] += d;
111 else slack[j] -= d;
112 }
113 }
114 }
115 int ans =0;
116 for(i =0; i < N; i++)
117 {
118 if(pre[i] !=-1)
119 ans -= g[pre[i]][i];
120 }
121 return ans;
122 }
123
124
125 int main()
126 {
127 int T;
128 scanf("%d", &T);
129 for(int cc =1;cc <= T;cc++)
130 {
131 BuildGraph();
132 int ans = KM();
133 printf("Case #%d: %d\n", cc, ans);
134 }
135 return0;
136 }