Submission #770644

#	Time	Username	Problem	Language	Result	Execution time	Memory
770644		bachhoangxuan	Election Campaign (JOI15_election_campaign)	C++17	100 / 100	173 ms	69276 KiB

election_campaign

// Judges with GCC >= 12 only needs Ofast
// #pragma GCC optimize("O3,no-stack-protector,fast-math,unroll-loops,tree-vectorize")
// MLE optimization
// #pragma GCC optimize("conserve-stack")
// Old judges
// #pragma GCC target("sse4.2,popcnt,lzcnt,abm,mmx,fma,bmi,bmi2")
// New judges. Test with assert(__builtin_cpu_supports("avx2"));
// #pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma,tune=native")
// Atcoder
// #pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma")
/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
- insert(x),erase(x)
- find_by_order(k): return iterator to the k-th smallest element
- order_of_key(x): the number of elements that are strictly smaller
*/
#include<bits/stdc++.h>
using namespace std;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
uniform_real_distribution<> pp(0.0,1.0);
#define int long long
#define ld long double
#define pii pair<int,int>
#define piii pair<pii,int>
#define mpp make_pair
#define fi first
#define se second
const int inf=1e18;
const int mod=1e9+7;
const int maxn=200005;
const int bl=650;
const int maxs=655;
const int maxm=200005;
const int maxq=500005;
const int maxl=18;
const int maxa=250000;
const int root=3;
int power(int a,int n){
    int res=1;
    while(n){
        if(n&1) res=res*a%mod;
        a=a*a%mod;n>>=1;
    }
    return res;
}
const int iroot=power(3,mod-2);
const int base=101;
namespace BIT{
    int n;
    vector<int> bit;
    void init(int N){
        n=N;
        bit.assign(n+1,0);
    }
    int query(int x){
        int res=0;
        for(int i=x;i>=1;i-=(i&(-i))) res+=bit[i];
        return res;
    }
    void update(int x,int val){
        for(int i=x;i<=n;i+=(i&(-i))) bit[i]+=val;
    }
    void update_range(int l,int r,int val){
        update(l,val);update(r+1,-val);
    }
}
namespace Tree{
    vector<vector<int>> edge,Min;
    vector<int> lg2,dep,L,R;
    int pos;
    int cmp(int u,int v){
        return (dep[u]<dep[v]?u:v);
    }
    int lca(int u,int v){
        u=L[u];v=L[v];
        if(u>v) swap(u,v);
        int p=lg2[v-u+1];
        return cmp(Min[u][p],Min[v-(1<<p)+1][p]);
    }
    int dist(int u,int v){
        return dep[u]+dep[v]-2*dep[lca(u,v)];
    }
    void dfs(int u,int p){
        L[u]=++pos;Min[pos][0]=u;
        dep[u]=dep[p]+1;
        for(int v:edge[u]){
            if(v==p) continue;
            dfs(v,u);Min[++pos][0]=u;
        }
        R[u]=pos;
    }
    void init(int n){
        lg2.assign(2*n+1,0);
        dep.assign(n+1,0);
        L.assign(n+1,0);
        R.assign(n+1,0);
        edge.resize(n+1);
        Min.assign(2*n+1,vector<int>(maxl,0));
    }
    void build(int n){
        init(n);
        for(int i=1;i<n;i++){
            int u,v;cin >> u >> v;
            edge[u].push_back(v);
            edge[v].push_back(u);
        }
        dfs(1,0);
        for(int i=2;i<=pos;i++) lg2[i]=lg2[i/2]+1;
        for(int i=1;i<maxl;i++){
            for(int j=1;j<=(pos-(1<<i)+1);j++) Min[j][i]=cmp(Min[j][i-1],Min[j+(1<<(i-1))][i-1]);
        }
    }
}
void solve(){
    int n;cin >> n;
    vector<vector<tuple<int,int,int>>> ss(n+1);
    vector<int> dp(n+1,0LL);
    Tree::build(n);
    BIT::init(2*n);
    int m;cin >> m;
    for(int i=1;i<=m;i++){
        int u,v,w;cin >> u >> v >> w;
        ss[Tree::lca(u,v)].push_back({u,v,w});
    }
    function<void(int,int)> dfs = [&](int u,int p){
        int sum=0;
        for(int v:Tree::edge[u]){
            if(v==p) continue;
            dfs(v,u);sum+=dp[v];
            //cout << u << ' ' << v << ' ' << dp[v] << ' ' << sum << '\n';
        }
        dp[u]=sum;
        //cout << sum << '\n';
        //cout << u << ' ' << sum << '\n';
        for(auto &[x,y,w]:ss[u]){
            //cout << x << ' ' << y << ' ' << w << '\n';
            int cur=sum+w+BIT::query(Tree::L[x])+BIT::query(Tree::L[y]);
            //cout << cur << '\n';
            dp[u]=max(dp[u],cur);
        }
        BIT::update_range(Tree::L[u],Tree::R[u],sum-dp[u]);
        //cout << u << ' ' << sum << ' ' << dp[u] << '\n';
    };
    dfs(1,0);
    cout << dp[1] << '\n';
}
signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);cout.tie(NULL);
    int test=1;//cin >> test;
    while(test--) solve();
}

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