60 lines
1.1 KiB
C++
60 lines
1.1 KiB
C++
#include<cstdio>
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#include<iostream>
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#include<vector>
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#include<queue>
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#include<cstring>
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using namespace std;
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struct node
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{
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int y,t;
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}edge[10009];
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int T[1009];
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vector<node> v[1009]; int n,m;
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int in[1009];
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void solve()
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{
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queue<int> q;
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for(int i=0;i<n;i++)
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if(in[i]==0)
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{
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q.push(i);
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T[i]=1;
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}
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while(!q.empty())
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{
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int x=q.front();q.pop();
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for(int i=0;i<v[x].size();i++)
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{
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int y=v[x][i].y;
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T[y]=max(T[y],T[x]+v[x][i].t);
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in[y]--;
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if(in[y]==0)
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{
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q.push(y);
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}
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}
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}
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int ans=0;
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for(int i=0;i<n;i++)
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ans=max(ans,T[i]);
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cout<<ans<<endl;
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}
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int main()
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{
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int a,b,t;
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while(scanf("%d%d",&n,&m)!=EOF)
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{
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memset(in,0,sizeof(in));
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memset(T,0,sizeof(T));
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for(int i=0;i<n;i++)
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v[i].clear();
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for(int i=0;i<m;i++)
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{
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scanf("%d%d%d",&a,&edge[i].y,&edge[i].t);
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v[a].push_back(edge[i]);
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in[edge[i].y]++;
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}
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solve();
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}
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}
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