Submission #92052

#	Time	Username	Problem	Language	Result	Execution time	Memory
92052		Kamisama	Election Campaign (JOI15_election_campaign)	C++14	100 / 100	409 ms	27768 KiB

election_campaign

#include <iostream>
#include <vector>

using namespace std;
const int maxn=1e5+7;

int n,m;
int par[maxn],lv[maxn],f[maxn][18];
int in[maxn],out[maxn],bit[maxn],dp[maxn];
vector<int> adj[maxn],road[maxn];
struct Query{int a,b,c;}q[maxn];

inline void Dfs(const int &u,const int &p){
    static int nVisit=0;
    in[u]=++nVisit;
    par[u]=p;
    lv[u]=lv[p]+1;
    f[u][0]=p;
    for(int i=1;i<18;i++) f[u][i]=f[f[u][i-1]][i-1];
    for(int v: adj[u]) if(v!=p) Dfs(v,u);
    out[u]=nVisit;
}

inline int Jump(int u,int k){
    for(int cur=0;k;k>>=1,cur++) if(k&1) u=f[u][cur];
    return u;
}

inline int Lca(int u,int v){
    if(lv[u]>lv[v]) swap(u,v);
    v=Jump(v,lv[v]-lv[u]);
    if(u==v) return u;
    for(int i=17;i>=0;i--) if(f[u][i]!=f[v][i]) u=f[u][i],v=f[v][i];
    return par[u];
}

inline void Update(int x,const int &val){
    for(;x<=n;x+=x&-x) bit[x]+=val;
}
inline int Get(int x){
    int res=0;
    for(;x;x-=x&-x) res+=bit[x];
    return res;
}

inline void Solve(const int &u,const int &p){
    int sumChild=0;
    for(int v: adj[u]) if(v!=p){
        Solve(v,u);
        sumChild+=dp[v];
    }
    dp[u]=sumChild;
    for(int i: road[u]){
        int a=q[i].a,b=q[i].b,c=q[i].c;
        dp[u]=max(dp[u],sumChild+Get(in[a])+Get(in[b])+c);
    }
    Update(in[u],sumChild-dp[u]); Update(out[u]+1,dp[u]-sumChild);
}

int main(){
    cin>>n;
    for(int i=1;i<n;i++){
        int u,v;
        cin>>u>>v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    Dfs(1,0);
    cin>>m;
    for(int i=1;i<=m;i++){
        cin>>q[i].a>>q[i].b>>q[i].c;
        road[Lca(q[i].a,q[i].b)].push_back(i);
    }
    Solve(1,0);
    cout<<dp[1];
    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 30 / 30
• Subtask 5: 10 / 10
• Subtask 6: 40 / 40