Submission #1128287

#	Time	Username	Problem	Language	Result	Execution time	Memory
1128287		ngokhanh	Election Campaign (JOI15_election_campaign)	C++20	100 / 100	314 ms	30744 KiB

election_campaign

#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for (int i=a;i<=b;i++)
#define rep2(i,a,b,c) for (int i=a;i<=b;i+=c)
#define rev(i,a,b) for (int i=a;i>=b;i--)
#define rev2(i,a,b,c) for (int i=a;i>=b;i-=c)
#define bit(i,j) ((i>>j)&1)
#define pii pair<int,int>
#define ull unsigned long long
#define pb push_back
#define pf push_front
#define ll long long
#define Fi first
#define Se second
#define on(n) __builtin_popcountll(n)
#define ld long double
#define __log2(x) 31-__builtin_clz(x)
#define Mask(x) (1LL<<x)
#define ALL(v) v.begin(),v.end()

const int MAXN=1e5+5;
const int mod=998244353;

int n,m,a,b,c,u,v,dp[MAXN];
vector<int> g[MAXN];bool ok=0;

struct Path{
    int x,y,w;
};

vector<Path> path[MAXN];

struct HLD{

    struct IT{

        int st[4*MAXN];

        void update(int x,int l,int r,int u,int v){
            if (u<l||r<u||l>r) return;
            if (l==r){
                st[x]+=v;
                return;
            }
            int mid=(l+r)/2;
            update(x*2,l,mid,u,v);
            update(x*2+1,mid+1,r,u,v);
            st[x]=st[x*2]+st[x*2+1];
        }


        int get(int x,int l,int r,int u,int v){
            if (v<l||r<u||l>r) return 0;
            if (u<=l&&r<=v) return st[x];
            int mid=(l+r)/2;
            return get(x*2,l,mid,u,v)+get(x*2+1,mid+1,r,u,v);
        }

        void Upd(int pos,int val) { update(1,1,n,pos,val); };

        int Get(int l,int r) { return get(1,1,n,l,r); };

    };

    IT sumdp,sumchilddp;
    int sz[MAXN],par[MAXN],depth[MAXN];
    int id[MAXN],head[MAXN],heavy[MAXN],cnt=0;

    void dfs(int u){
        sz[u]=1;
        for (int v:g[u]){
            if (v==par[u]) continue;
            par[v]=u;
            depth[v]=depth[u]+1;
            dfs(v);
            sz[u]+=sz[v];
            if (heavy[u]==-1||sz[v]>sz[heavy[u]]) heavy[u]=v;
        }
    }

    void Decompose(int u,int t){
        id[u]=++cnt;
        head[u]=t;
        if (heavy[u]!=-1) Decompose(heavy[u],t);
        for (int v:g[u]){
            if (v==par[u]||v==heavy[u]) continue;
            Decompose(v,v);
        }
    }

    int lca(int u,int v){
        for (;head[u]!=head[v];v=par[head[v]])
            if (depth[head[u]]>depth[head[v]]) swap(u,v);
        if (depth[u]>depth[v]) swap(u,v);
        return u;
    }

    void Updsumdp(int u,int val) {sumdp.Upd(id[u],val);};
    void Updsumchilddp(int u,int val) {sumchilddp.Upd(id[u],val);};

    int CalcPath(int u,int v){
        int Total=0,Exclu=0;
        for (;head[u]!=head[v];v=par[head[v]]){
            if (depth[head[u]]>depth[head[v]]) swap(u,v);
            Total+=sumchilddp.Get(id[head[v]],id[v]);
            Exclu+=sumdp.Get(id[head[v]],id[v]);
        }
        if (depth[u]>depth[v]) swap(u,v);
        Total+=sumchilddp.Get(id[u],id[v]);
        Exclu+=sumdp.Get(id[u],id[v]);
        return Total-Exclu;
    }

    void Init(){
        memset(heavy,-1,sizeof(heavy));
        dfs(1);
        Decompose(1,1);
    }

};

HLD tree;

void dfs(int u,int p){
    for (int v:g[u]){
        if (v==p) continue;
        dfs(v,u);
    }
    int sum=0;
    for (int v:g[u]) if (v!=p) sum+=dp[v];
    dp[u]=sum;
    tree.Updsumchilddp(u,sum);
    if (!path[u].empty())
        for (Path tmp:path[u]) dp[u]=max(dp[u],tree.CalcPath(tmp.x,tmp.y)+tmp.w);
    tree.Updsumdp(u,dp[u]);
}

void solution(){
    cin >> n;
    rep(i,1,n-1){
        cin >> u >> v;
        g[u].pb(v);
        g[v].pb(u);
    }
    tree.Init();
    cin >> m;
    rep(i,1,m){
        cin >> a >> b >> c;
        path[tree.lca(a,b)].pb({a,b,c});
    }
    dfs(1,-1);
    cout << dp[1];
}

int32_t main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int test=1;
    while(test--)
        solution();
}

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