[CODEVS1914] 运输问题（最小费用最大流）

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水题。

建图都不想说了

 

——代码

  1 #include <queue>
  2 #include <cstdio>
  3 #include <cstring>
  4 #include <iostream>
  5 #define INF 1e9
  6 #define M 101
  7 #define N 100001
  8 #define min(x, y) ((x) < (y) ? (x) : (y))
  9 
 10 int n, m, cnt, s, t;
 11 int a[M], b[M], map[M][M], dis[N], pre[N];
 12 int head[N], to[N << 1], val[N << 1], cost[N << 1], next[N << 1];
 13 bool vis[N];
 14 
 15 inline int read()
 16 {
 17     int x = 0, f = 1;
 18     char ch = getchar();
 19     for(; !isdigit(ch); ch = getchar()) if(ch == '-') f = -1;
 20     for(; isdigit(ch); ch = getchar()) x = (x << 1) + (x << 3) + ch - '0';
 21     return x * f;
 22 }
 23 
 24 inline void add(int x, int y, int z, int c)
 25 {
 26     to[cnt] = y;
 27     val[cnt] = z;
 28     cost[cnt] = c;
 29     next[cnt] = head[x];
 30     head[x] = cnt++;
 31 }
 32 
 33 inline bool spfa()
 34 {
 35     int i, u, v;
 36     std::queue <int> q;
 37     memset(vis, 0, sizeof(vis));
 38     memset(pre, -1, sizeof(pre));
 39     memset(dis, 127 / 3, sizeof(dis));
 40     q.push(s);
 41     dis[s] = 0;
 42     while(!q.empty())
 43     {
 44         u = q.front(), q.pop();
 45         vis[u] = 0;
 46         for(i = head[u]; i ^ -1; i = next[i])
 47         {
 48             v = to[i];
 49             if(val[i] && dis[v] > dis[u] + cost[i])
 50             {
 51                 dis[v] = dis[u] + cost[i];
 52                 pre[v] = i;
 53                 if(!vis[v])
 54                 {
 55                     q.push(v);
 56                     vis[v] = 1;
 57                 }
 58             }
 59         }
 60     }
 61     return pre[t] ^ -1;
 62 }
 63 
 64 inline int dinic()
 65 {
 66     int i, d, sum = 0;
 67     while(spfa())
 68     {
 69         d = 1e9;
 70         for(i = pre[t]; i ^ -1; i = pre[to[i ^ 1]]) d = min(d, val[i]);
 71         for(i = pre[t]; i ^ -1; i = pre[to[i ^ 1]])
 72         {
 73             val[i] -= d;
 74             val[i ^ 1] += d;
 75         }
 76         sum += dis[t] * d;
 77     }
 78     return sum;
 79 }
 80 
 81 int main()
 82 {
 83     int i, j;
 84     m = read();
 85     n = read();
 86     s = 0, t = n + m + 1;
 87     memset(head, -1, sizeof(head));
 88     for(i = 1; i <= m; i++)
 89     {
 90         a[i] = read();
 91         add(s, i, a[i], 0);
 92         add(i, s, 0, 0);
 93     }
 94     for(i = 1; i <= n; i++)
 95     {
 96         b[i] = read();
 97         add(i + m, t, b[i], 0);
 98         add(t, i + m, 0, 0);
 99     }
100     for(i = 1; i <= m; i++)
101         for(j = 1; j <= n; j++)
102         {
103             map[i][j] = read();
104             add(i, j + m, INF, map[i][j]);
105             add(j + m, i, 0, -map[i][j]);
106         }
107     printf("%d\n", dinic());
108     cnt = 0;
109     memset(head, -1, sizeof(head));
110     for(i = 1; i <= m; i++)
111     {
112         add(s, i, a[i], 0);
113         add(i, s, 0, 0);
114     }
115     for(i = 1; i <= n; i++)
116     {
117         add(i + m, t, b[i], 0);
118         add(t, i + m, 0, 0);
119     }
120     for(i = 1; i <= m; i++)
121         for(j = 1; j <= n; j++)
122         {
123             add(i, j + m, INF, -map[i][j]);
124             add(j + m, i, 0, map[i][j]);
125         }
126     printf("%d\n", -dinic());
127     return 0;
128 }
View Code

 

posted @ 2017-06-14 11:14  zht467  阅读(172)  评论(0)  编辑  收藏  举报