2012成都赛区网络赛 hdu4292

论文题啦。。。。与poj3281一摸一样....

每个人有自己喜欢的食物和饮料，算作一个从源到汇的流。关键地方是将人拆成两个点，分别连源和汇，这样就是多源多汇的最大流了。

为什么要拆点呢，因为每个人只能算一种食物一种饮料，不然就有不同的食物流到不同的饮料了。。。

#include<stdio.h>
#include<string.h>
#include<stdlib.h>

#define NODE_SIZE 10010
#define EDGE_SIZE 200005
#define INF 0x7fffff

struct info{
int s,e,f,next;
}edge[EDGE_SIZE];

int edge_num;
int head[NODE_SIZE];
int Que[NODE_SIZE];
int level[NODE_SIZE];
int cur_head[NODE_SIZE];
int n,f,d;
int fd[NODE_SIZE],dr[NODE_SIZE];
int edge_stack[4 * NODE_SIZE + 4 * EDGE_SIZE];
int stack_top;
int source,sink;

void add_edge(int s,int e,int f)
{
int t = edge_num;
edge[t].s = s;
edge[t].e = e;
edge[t].f = f;
edge[t].next = head[s];
head[s] = edge_num ++;
}

int BFS()
{
int fr,tp,cur,next,e;
memset(level,-1,sizeof(level));
Que[0] = source;
level[source] = 0;
for( fr = 0,tp = 1; fr != tp; fr = (fr + 1)%NODE_SIZE ){
cur = Que[fr];
for( e = head[cur]; e != -1; e = edge[e].next ){
next = edge[e].e;
if( edge[e].f && level[next] == -1 ){
Que[tp] = next;
level[next] = level[cur] + 1;
tp = (tp + 1)%NODE_SIZE;
}
}
}
return level[sink] != -1;
}

int find_max_flow()
{
int cur,e,next;
int i,index,min_limit;
int res = 0;

memcpy(cur_head,head,sizeof(head));
cur = source;

stack_top = 0;
while( stack_top >= 0 ){
if( cur == sink ){
min_limit = INF;
for( i = stack_top - 1; i >= 0 ; i -- ){
e = edge_stack[i];
if( edge[e].f <= min_limit ){
min_limit = edge[e].f;
index = i;
}
}
res += min_limit;

for( i = stack_top - 1; i >= 0; i -- ){
e = edge_stack[i];
edge[e].f -= min_limit;
edge[e ^ 1].f += min_limit;
}

stack_top = index;

cur = edge[ edge_stack[ stack_top ] ].s;
}
for( e = cur_head[cur]; e != -1; e = edge[e].next ){
cur_head[cur] = e;
next = edge[e].e;
if( edge[e].f && level[next] == level[cur] + 1 ){
edge_stack[stack_top ++]  = e;
cur = next;
break;
}
}
if( e == -1 ){
stack_top --;
level[cur] = -2;
cur = edge[ edge_stack[stack_top] ].s;
}
}
return res;
}

int main()
{
int res;
while( scanf("%d%d%d",&n,&f,&d) != EOF )
{
char str[205];
for(int i=1;i<=f;i++) scanf("%d",&fd[i]);
for(int i=1;i<=d;i++) scanf("%d",&dr[i]);
edge_num=0;
memset(head,-1,sizeof(head));
for(int i=1;i<=n;i++)
{
scanf("%s",str);
for(int j=1;j<=f;j++)
if(str[j-1]=='Y') {add_edge(j+2*n,i,1); add_edge(i,j+2*n,0);}
}
for(int i=1;i<=n;i++)
{
scanf("%s",str);
for(int j=1;j<=d;j++)
if(str[j-1]=='Y') {add_edge(i+n,2*n+f+j,1);add_edge(2*n+f+j,i+n,0);}
}
for(int i=1;i<=n;i++)
{add_edge(i,i+n,1); add_edge(i+n,i,0);}
for(int i=1; i<=f; i++)
{add_edge(0,i+2*n,fd[i]); add_edge(i+2*n,0,0);}
for(int i=1; i<=d; i++)
{add_edge(i+2*n+f,2*n+f+d+1,dr[i]); add_edge(2*n+f+d+1,i+2*n+f,0);}
source=0; sink=2*n+f+d+1;

res = 0;
while( BFS() ){
res += find_max_flow();
}
printf("%d\n",res);
}
return 0;
}