Submission #3712511

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Source Code Expand

//test https://blog.csdn.net/rising_shit/article/details/80739593
#include<iostream>
#include<stdio.h>
#include<string.h>
#include<algorithm>
#define maxn 2005
#define _x1 x1
#define _x2 x2
using namespace std;
typedef long long ll;
const ll mod=1e9+7;
int n,m;
ll v;
int fa[maxn],id[maxn],x[maxn],y[maxn];
ll w[maxn];
int getfa(int now)
{
	return fa[now]==now ? now : fa[now]=getfa(fa[now]);
}
int cmp(int i,int j)
{
	return w[i]<w[j];
}
ll kruskal(int now)
{
	for(int i=1;i<=n;i++) fa[i]=i;
	ll ans=0;
	if(now)
		fa[x[now]]=y[now],ans+=w[now];
	for(int i=1;i<=m;i++)
	{
		int pos=id[i];
		int x1=getfa(x[pos]),y1=getfa(y[pos]);
		if(x1!=y1)
		{
			ans+=w[pos];
			fa[x1]=y1;
		}
	}
	return ans;
}
ll quickpow(ll p,ll k)
{
	ll ans=1;
	while(k)
	{
		if(k&1)
			ans=(ans*p)%mod;
		p=(p*p)%mod;
		k>>=1;
	}
	return ans;
}
int main()
{
	scanf("%d%d%lld",&n,&m,&v);
	for(int i=1;i<=m;i++)
		scanf("%d%d%lld",&x[i],&y[i],&w[i]),id[i]=i;
	sort(id+1,id+1+m,cmp);
 
	ll temp=kruskal(0);
 
	if(temp>v)
	return printf("0\n"),0;
 
	if(temp==v)
	{
		int cnt1=0,cnt2=0;
		for(int i=1;i<=m;i++)
		{
			if(kruskal(i)==temp)
				cnt1++;
			else
				cnt2++;
		}
		ll res1=(quickpow(2,cnt1)-2+mod)%mod;
		ll res2=quickpow(2,cnt2)%mod;
		return printf("%lld\n",res1*res2%mod),0;
	}
	else
	{
		int cnt1=0,cnt2=0;
		for(int i=1;i<=m;i++)
		{
			ll res1=kruskal(i);
			if(res1==v)
				cnt1++;
			else if(res1>v)
				cnt2++;
		}
		ll res1=2ll*((quickpow(2,cnt1)-1+mod)%mod)%mod;
		ll res2=quickpow(2,cnt2);
		printf("%lld\n",res1*res2%mod);
	}
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:56:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d%lld",&n,&m,&v);
                            ^
./Main.cpp:58:46: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%lld",&x[i],&y[i],&w[i]),id[i]=i;
                                              ^

Judge Result