OJ-Problems-Source/HDOJ/3666_autoAC.cpp
2016-09-04 14:13:02 +08:00

96 lines
1.8 KiB
C++

#include<stdio.h>
#include<string.h>
#include<math.h>
#include<queue>
using namespace std;
const int V = 808, E=400000;
const double INF=1e5;
double d[V],cost[E];
int n,m,verNum;
int head[V],pnt[E],nxt[E],e;
int cnt[V];
double u,l;
void addedge(int u,int v,double c)
{
pnt[e]=v;
cost[e]=c;
nxt[e]=head[u];
head[u]=e++;
}
bool relax(int u,int v,double w)
{
if(d[v]>d[u]+w)
{
d[v]=d[u]+w;
return 1;
}
return 0;
}
int spfa()
{
int vis[V];
int i;
//int Q[E];
queue<int> Q;
for(i=1;i<verNum;++i)
{
cnt[i] = 0;
d[i]=INF;
vis[i]=0;
}
vis[0]=1;
d[0]=0;
cnt[0] = 1;
//int top=1;
//Q[0]=0;
Q.push(0);
int u,v;
double w;
int nm = sqrt(verNum * 1.0); //涓寮归借跺澶╁ㄦ
while(!Q.empty())
{
//u=Q[--top];
u = Q.front();
Q.pop();
vis[u]=0;
for(i=head[u];i!=-1;i=nxt[i])
{
v=pnt[i];
w=cost[i];
if(relax(u,v,w) && !vis[v])
{
if(++cnt[v] > nm)
return 0;
//Q[top++]=v;
Q.push(v);
vis[v]=1;
}
}
}
return 1;
}
int main()
{
while(scanf("%d%d%lf%lf",&n,&m,&l,&u) == 4)
{
double c,ll = log(l),uu = log(u);
int i,j;
verNum = n + m;
memset(head,-1,sizeof(head));
e = 0;
for(i = 0; i < n; ++i)
for(j = 0; j < m; ++j)
{
scanf("%lf",&c);
c = log(c);
addedge(i,j+n,c-ll);
addedge(j+n,i,uu-c);
}
if(spfa())
printf("YES\n");
else
printf("NO\n");
}
return 0;
}