BZOJ2039 [2009国家集训队]employ人员雇佣

一开始就知道是最小割模型，然后开始乱搞建图，发现自己想错了。。。

Orz PoPoQQQ，还给蒟蒻提供了很多帮助！

 

  1 /**************************************************************
  2     Problem: 2039
  3     User: rausen
  4     Language: C++
  5     Result: Accepted
  6     Time:5984 ms
  7     Memory:64264 kb
  8 ****************************************************************/
  9  
 10 #include <cstdio>
 11 #include <cstring>
 12 #include <algorithm>
 13  
 14 using namespace std;
 15 typedef long long ll;
 16 const int N = 1005;
 17 const int M = 4 * N * (N + 5);
 18 const ll inf = (ll) 1e60;
 19  
 20 struct edge {
 21   int next, to;
 22   ll f;
 23   edge() {}
 24   edge(int _n, int _t, ll _f) : next(_n), to(_t), f(_f) {}
 25 } e[M];
 26  
 27 int n, S, T;
 28 int first[N], tot = 1;
 29 ll ans, a[N];
 30 int q[N], d[N];
 31  
 32 int read() {
 33   int x = 0;
 34   char ch = getchar();
 35   while (ch < '0' || '9' < ch)
 36     ch = getchar();
 37   while ('0' <= ch && ch <= '9')
 38     (x *= 10) += ch - '0', ch = getchar();
 39   return x;
 40 }
 41  
 42 inline void add_edges(int x, int y, ll z) {
 43   e[++tot] = edge(first[x], y, z), first[x] = tot;
 44   e[++tot] = edge(first[y], x, 0), first[y] = tot;
 45 }
 46  
 47 inline void Add_Edges(int x, int y, int z) {
 48   add_edges(x, y, z);
 49   add_edges(y, x, z);
 50 }
 51  
 52 #define y e[x].to
 53 #define p q[l]
 54 bool bfs() {
 55   int l, r, x;
 56   memset(d, -1, sizeof(d));
 57   d[q[1] = S] = 1;
 58   for (l = r = 1; l != r + 1; ++l)
 59     for (x = first[p]; x; x = e[x].next)
 60       if (!~d[y] && e[x].f) {
 61     d[q[++r] = y] = d[p] + 1;
 62     if (y == T) return 1;
 63       }
 64   return 0;
 65 }
 66 #undef p
 67  
 68 ll dfs(int p, ll lim) {
 69   if (p == T || !lim) return lim;
 70   int x;
 71   ll tmp, rest = lim;
 72   for (x = first[p]; x && rest; x = e[x].next) 
 73     if (d[y] == d[p] + 1 && ((tmp = min(e[x].f, rest)) > 0)) {
 74       rest -= (tmp = dfs(y, tmp));
 75       e[x].f -= tmp, e[x ^ 1].f += tmp;
 76       if (!rest) return lim;
 77     }
 78   if (rest) d[p] = -1;
 79   return lim - rest;
 80 }
 81 #undef y
 82  
 83 ll Dinic() {
 84   ll res = 0;
 85   while (bfs())
 86     res += dfs(S, inf);
 87   return res;
 88 }
 89  
 90 int main() {
 91   int i, j, E;
 92   n = read();
 93   S = n + 1, T = n + 2;
 94   for (i = 1; i <= n; ++i)
 95     add_edges(i, T, read());
 96   for (i = 1; i <= n; ++i)
 97     for (j = 1; j <= n; ++j) {
 98       ans += (E = read());
 99       if (i < j) {
100     a[i] += E, a[j] += E;
101     Add_Edges(i, j, (ll) E << 1);
102       }
103     }
104   for (i = 1; i <= n; ++i)
105     add_edges(S, i, a[i]);
106   printf("%lld\n", ans - Dinic());
107   return 0;
108 }
View Code

(p.s. 新的最大流模板get！)

posted on 2015-01-29 23:29  Xs酱~  阅读(226)  评论(0)  编辑  收藏  举报