OJ-Problems-Source/HDOJ/3038_autoAC.cpp
2016-08-30 22:34:56 +08:00

58 lines
997 B
C++

#include<stdio.h>
#define MAXN 200010
int f[MAXN],r[MAXN];
int find(int x)
{
if(x==f[x])
return f[x];
int t=find(f[x]);
r[x]=r[x]+r[f[x]];
f[x]=t;
return f[x];
}
int fun(int x,int y)
{
if(x>y)
return x-y;
else y-x;
}
int Union(int x,int y,int sum)
{
int a=find(x);
int b=find(y);
if(a==b)
{
if(fun(r[x],r[y])==sum)
return 0;
else return 1;
}
else
{
f[a]=b;
r[a]=r[y]+sum-r[x];
return 0;
}
}
int main()
{
int n,m,i,ans,a,b,s;
while(scanf("%d %d",&n,&m)!=EOF)
{
ans=0;
for(i=0;i<=n;i++)
{
f[i]=i;
r[i]=0;
}
for(i=1;i<=m;i++)
{
scanf("%d %d %d",&a,&b,&s);
a--;
if(Union(a,b,s))
ans++;
}
printf("%d\n",ans);
}
return 0;
}