Submission #1108959

#TimeUsernameProblemLanguageResultExecution timeMemory
1108959doducanhFactories (JOI14_factories)C++14
0 / 100
22 ms129872 KiB
///breaker //#include "factories.h" #include<bits/stdc++.h> using namespace std; #define ll long long #define fi first #define se second #define ii pair<int,int> #define mp make_pair #define in(x) freopen(x,"r",stdin) #define out(x) freopen(x,"w",stdout) #define bit(x,i) ((x>>i)&1) #define lc (id<<1) #define rc ((id<<1)^1) const int maxn=5e5+7; const ll inf=1e18+7; vector<ii>adj[maxn]; int sz[maxn]; bool used[maxn]; int p[25][maxn]; ll up[25][maxn]; ll minn[maxn]; int h[maxn]; vector<int>ancestors[maxn]; int dfs(int u,int par) { sz[u]=1; for(ii pp:adj[u]){ int v=pp.fi; if(v==par||used[v])continue; sz[u]+=dfs(v,u); } return sz[u]; } void dfs1(int u,int par) { for(ii pp:adj[u]){ int v=pp.fi; int w=pp.se; if(v==par)continue; p[0][v]=u; up[0][v]=w; h[v]=h[u]+1; dfs1(v,u); } } void dfs2(int u,int par,int cen) { ancestors[u].push_back(cen); for(ii pp:adj[u]){ int v=pp.fi; if(v==par||used[v])continue; dfs2(v,u,cen); } } int getcen(int u,int par,int treesize) { for(ii pp:adj[u]){ int v=pp.fi; if(v==par||used[v])continue; if((sz[v]<<1)>treesize)return getcen(v,u,treesize); } return u; } void buildcen(int u,int par) { int C=getcen(u,0,dfs(u,0)); used[C]=1; dfs2(C,0,C); for(ii pp:adj[u]){ int v=pp.fi; if(v==par||used[v])continue; buildcen(v,C); } } ll path(int u,int v) { if(h[u]<h[v])swap(u,v); int del=h[u]-h[v]; ll ans=0; for(int i=20;i>=0;i--)if(bit(del,i)){ ans+=up[i][u]; u=p[i][u]; } if(u==v)return ans; for(int i=20;i>=0;i--)if(p[i][u]!=p[i][v]){ ans+=up[i][u]; ans+=up[i][v]; u=p[i][u]; v=p[i][v]; } ans+=up[0][u]; ans+=up[0][v]; return ans; } void Init(int N,int A[],int B[],int D[]) { for(int i=0;i<N-1;i++){ adj[A[i]].push_back({B[i],D[i]}); adj[B[i]].push_back({A[i],D[i]}); } dfs1(0,0); for(int i=1;i<=20;i++){ for(int j=0;j<N;j++){ p[i][j]=p[i-1][p[i-1][j]]; up[i][j]=up[i-1][j]+up[i-1][p[i-1][j]]; } } buildcen(0,0); for(int i=0;i<N;i++){ minn[i]=inf; } } long long Query(int S, int X[], int T, int Y[]) { for(int i=0;i<S;i++){ for(int y:ancestors[X[i]]){ minn[y]=min(minn[y],path(X[i],y)); } } ll ans=inf; for(int i=0;i<T;i++){ for(int y:ancestors[Y[i]]){ ans=min(ans,minn[y]+path(Y[i],y)); } } for(int i=0;i<S;i++){ for(int y:ancestors[X[i]]){ minn[y]=inf; } } return ans; } /* stuff you should look for * int overflow, array bounds * special cases (n=1?) * do smth instead of nothing and stay organized * WRITE STUFF DOWN * DON'T GET STUCK ON ONE APPROACH */
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