AC#9#10求调
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  • 楼主_Liyx_
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  • 发布时间2024/12/7 12:59
  • 上次更新2024/12/7 16:22:27
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AC#9#10求调
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_Liyx_楼主2024/12/7 12:59

rt

#include<bits/stdc++.h>
using namespace std;
#define N 80005
struct node{
	int v,w,W; 
};
struct edge{
	int v,w;
};
vector<node> g[N];
vector<edge> G[N];
int n,m,s;
int dfn[N],low[N],buc[N],sum[N],scc[N],num,cnt,dp[N];
stack<int> stk;
void Tarjan(int u){
	dfn[u]=low[u]=++cnt;
	buc[u]=1;
	stk.push(u);
	for(auto ed:g[u]){
		int v=ed.v,w=ed.W;
		if(!dfn[v]){
			Tarjan(v);
			low[u]=min(low[u],low[v]);
		}
		else if(buc[v]) low[u]=min(low[u],dfn[v]);
	}
	if(dfn[u]==low[u]){
		num++;
		int y;
		do{
			y=stk.top();
			stk.pop();
			scc[y]=num;
			buc[y]=0;
		}while(y!=u);
	}
}
int dis[N];
bool vis[N];
void SPFA(){
	int ans=0;
	queue<int> q;
	s=scc[s];
	q.push(s);
	dis[s]=sum[s];
	while(!q.empty()){
		int u=q.front();
		q.pop();
		vis[u]=0;
		for(auto ed:G[u]){
			int v=ed.v,w=ed.w;
			if(dis[v]<dis[u]+w){
				dis[v]=dis[u]+w;
				if(!vis[v]){
					q.push(v);
					vis[v]=1;
				}
			}
		}
	}
	for(int i=1;i<=num;i++) ans=max(ans,dis[i]);
	cout<<ans;
}
int main(){
	cin>>n>>m;
	for(int i=1;i<=m;i++){
		int u,v,w,tmp,W;
		double h;
		cin>>u>>v>>w>>h;
		tmp=W=w;
		h*=10;
		while(tmp){
			tmp=tmp*h/10;
			W+=tmp;
		}
		g[u].push_back({v,w,W});
	}
	for(int i=1;i<=n;i++) if(!dfn[i]) Tarjan(i);
	for(int u=1;u<=num;u++)
		for(auto ed:g[u]){
			int v=ed.v;
			if(scc[u]==scc[v]) sum[scc[u]]+=ed.W;
			else G[scc[u]].push_back({scc[v],ed.w});
		}
	cin>>s;
	SPFA();
	return 0;

} 

为什么后两个数据点过了,前面没过

2024/12/7 12:59
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