BZOJ1066: [SCOI2007]蜥蜴

  1 #include <iostream>
  2 #include <cstdio>
  3 #include <cstring>
  4 #include <cstdlib>
  5 #include <algorithm>
  6 #include <cmath>
  7 #include <queue>
  8 #include <vector>
  9 #define min(a, b) ((a) < (b) ? (a) : (b))
 10 #define max(a, b) ((a) > (b) ? (a) : (b))
 11 #define abs(a) ((a) < 0 ? (-1 * (a)) : (a))
 12 inline void swap(int &a, int &b)
 13 {
 14     long long tmp = a;a = b;b = tmp;
 15 }
 16 inline void read(int &x)
 17 {
 18     x = 0;char ch = getchar(), c = ch;
 19     while(ch < ‘0‘ || ch > ‘9‘) c = ch, ch = getchar();
 20     while(ch <= ‘9‘ && ch >= ‘0‘) x = x * 10 + ch - ‘0‘, ch = getchar();
 21     if(c == ‘-‘)x = -x;
 22 }
 23 
 24 const int INF = 0x3f3f3f3f;
 25 const int MAXN = 500;
 26 const int MAXM = 2000000;
 27 
 28 struct Edge
 29 {
 30     int u,v,w,nxt;
 31     Edge(int _u, int _v, int _w, int _nxt){u = _u;v = _v;w = _w;nxt = _nxt;}
 32     Edge(){}
 33 }edge[MAXM << 1];
 34 int head[200000], cnt = 1, q[200000], h[200000], ans = 0, S, T;
 35 
 36 inline void insert(int a, int b, int c)
 37 {
 38     edge[++cnt] = Edge(a,b,c,head[a]);
 39     head[a] = cnt;
 40     edge[++cnt] = Edge(b,a,0,head[b]);
 41     head[b] = cnt;
 42 }
 43 
 44 bool bfs()
 45 {
 46     int he = 0, ta = 1;
 47     memset(h, -1, sizeof(h));
 48     q[he] = S, h[S] = 0;
 49     while(he < ta)
 50     {
 51         int now = q[he ++];
 52         for(int pos = head[now];pos;pos = edge[pos].nxt)
 53         {
 54             int v = edge[pos].v;
 55             if(h[v] == -1 && edge[pos].w)
 56             {
 57                 h[v] = h[now] + 1;
 58                 q[ta ++] = v;
 59             }
 60         }
 61     }
 62     return h[T] != -1;
 63 }
 64 
 65 int dfs(int x, int f)
 66 {
 67     if(x == T) return f;
 68     int w, used = 0;
 69     for(int pos = head[x];pos;pos = edge[pos].nxt)
 70     {
 71         int v = edge[pos].v;
 72         if(h[v] == h[x] + 1)
 73         {
 74             w = dfs(v, min(f - used, edge[pos].w));
 75             edge[pos].w -= w;
 76             edge[pos ^ 1].w += w;
 77             used += w;
 78             if(used == f) return f;
 79         }
 80     }
 81     if(!used) h[x] = -1;
 82     return used;
 83 }
 84 
 85 void dinic()
 86 {
 87     while(bfs()) ans += dfs(S, INF);
 88 }
 89 
 90 int r,c,d,g[MAXN][MAXN],x[MAXN << 1],y[MAXN << 1],w[MAXN << 1],tot,t;
 91 char s[MAXN][MAXN];
 92 
 93 int main()
 94 {
 95     S = 100000, T = 100001;
 96     read(r), read(c), read(d);
 97     for(register int i = 1;i <= r;++ i)
 98     {
 99         scanf("%s", s[i] + 1);
100         for(register int j = 1;j <= c;++ j)
101             g[i][j] = s[i][j] - ‘0‘;
102     }
103     for(register int i = 1;i <= r;++ i)
104         scanf("%s", s[i] + 1);
105     for(register int i = 1;i <= r;++ i)
106         for(register int j = 1;j <= c;++ j)
107         {
108             if(s[i][j] == ‘L‘) ++ t;
109             if(g[i][j] > 0)
110             {
111                 ++ tot;x[tot] = i, y[tot] = j, w[tot] = g[i][j];
112             }
113         } 
114     for(register int i = 1;i <= tot;++ i)
115     {
116         int tmp = min(x[i], min(y[i], min(r - x[i] + 1, c - y[i] + 1)));
117         if(tmp <= d) 
118             insert(i + tot, T, INF);
119         if(s[x[i]][y[i]] == ‘L‘) 
120             insert(S, i, 1);
121         insert(i, i + tot, w[i]);
122     }
123     for(register int i = 1;i <= tot;++ i)
124         for(register int j = i + 1;j <= tot;++ j)
125         {
126             if((x[i] - x[j]) * (x[i] - x[j]) + (y[i] - y[j]) * (y[i] - y[j]) <= d * d)
127                 insert(i + tot, j, INF), insert(j + tot, i, INF);
128         }
129     dinic();
130     printf("%d", t - ans);
131     return 0;
132 }