hdu 4292 Food 网络流

  1 #include<bits/stdc++.h>
  2 using namespace std;
  3 #define pb(x) push_back(x)
  4 #define ll long long
  5 #define mk(x, y) make_pair(x, y)
  6 #define lson l, m, rt<<1
  7 #define mem(a) memset(a, 0, sizeof(a))
  8 #define rson m+1, r, rt<<1|1
  9 #define mem1(a) memset(a, -1, sizeof(a))
 10 #define mem2(a) memset(a, 0x3f, sizeof(a))
 11 #define rep(i, a, n) for(int i = a; i<n; i++)
 12 #define ull unsigned long long
 13 typedef pair<int, int> pll;
 14 const double PI = acos(-1.0);
 15 const double eps = 1e-8;
 16 const int mod = 1e9+7;
 17 const int inf = 1061109567;
 18 const int dir[][2] = { {-1, 0}, {1, 0}, {0, -1}, {0, 1} };
 19 const int maxn = 8e4+5;
 20 int head[maxn*4], s, t, num, q[maxn], dis[maxn];
 21 struct node
 22 {
 23     int to, nextt, c;
 24 }e[maxn*4];
 25 void init() {
 26     mem1(head);
 27     num = 0;
 28 }
 29 void add(int u, int v, int c) {
 30     e[num].to = v; e[num].nextt = head[u]; e[num].c = c; head[u] = num++;
 31     e[num].to = u; e[num].nextt = head[v]; e[num].c = 0; head[v] = num++;
 32 }
 33 int bfs() {
 34     int u, v, st = 0, ed = 0;
 35     mem(dis);
 36     dis[s] = 1;
 37     q[ed++] = s;
 38     while(st<ed) {
 39         u = q[st++];
 40         for(int i = head[u]; ~i; i = e[i].nextt) {
 41             v = e[i].to;
 42             if(e[i].c&&!dis[v]) {
 43                 dis[v] = dis[u]+1;
 44                 if(v == t)
 45                     return 1;
 46                 q[ed++] = v;
 47             }
 48         }
 49     }
 50     return 0;
 51 }
 52 int dfs(int u, int limit) {
 53     if(u == t)
 54         return limit;
 55     int cost = 0;
 56     for(int i = head[u]; ~i; i = e[i].nextt) {
 57         int v = e[i].to;
 58         if(e[i].c&&dis[u] == dis[v]-1) {
 59             int tmp = dfs(v, min(limit-cost, e[i].c));
 60             if(tmp>0) {
 61                 e[i].c -= tmp;
 62                 e[i^1].c += tmp;
 63                 cost += tmp;
 64                 if(cost == limit)
 65                     break;
 66             } else {
 67                 dis[v] = -1;
 68             }
 69         }
 70     }
 71     return cost;
 72 }
 73 int dinic() {
 74     int ans = 0;
 75     while(bfs()) {
 76         ans += dfs(s, inf);
 77     }
 78     return ans;
 79 }
 80 char c[205];
 81 int main()
 82 {
 83     int n, f, d, x;
 84     while(cin>>n>>f>>d) {
 85         init();
 86         s = 0, t = f+2*n+d+1;
 87         for(int i = 1; i<=f; i++) {
 88             scanf("%d", &x);
 89             add(s, i, x);
 90         }
 91         for(int i = 1; i<=d; i++) {
 92             scanf("%d", &x);
 93             add(f+2*n+i, t, x);
 94         }
 95         for(int k = 0; k<2; k++) {
 96             for(int i = 1; i<=n; i++) {
 97                 scanf("%s", c);
 98                 int len = strlen(c);
 99                 for(int j = 0; j<len; j++) {
100                     if(c[j]==‘Y‘) {
101                         if(k==0) {
102                             add(j+1, f+i, 1);
103                         } else {
104                             add(f+n+i, j+1+f+2*n, 1);
105                         }
106                     }
107                 }
108             }
109         }
110         for(int i = 1; i<=n; i++) {
111             add(i+f, i+n+f, 1);
112         }
113         int ans = dinic();
114         cout<<ans<<endl;
115     }
116 }