제출 #1153895

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1153895		salmon	Sjekira (COCI20_sjekira)	C++20	0 / 110	59 ms	18244 KiB

sjekira

#include <bits/stdc++.h>
using namespace std;

int N;
int lst[100100];
int invlst[100100];
int cont = 0;
int pre[100100];
int post[100100];
vector<int> adjlst[100100];
int parent[100100];
bool done[100100];
int u,v;

struct node{

    int s, e, m;
    node *l, *r;
    pair<int,int> v;

    node(int S, int E){
        s = S;
        e = E;
        m = (s + e)/2;

        if(s != e){
            l = new node(s,m);
            r = new node(m + 1, e);

            v = max(l -> v, r -> v);
        }
        else v = {lst[invlst[s]],invlst[s]};
    }

    pair<int,int> query(int S,int E){
        if(S <= s && e <= E) return v;

        pair<int,int> V = {-1,-1};

        if(S <= m) V = max(l -> query(S,E),V);
        if(m < E) V = max(r -> query(S,E),V);

        return V;
    }

    void update(int i){
        if(s == e){
            v = {-1,-1};
            return;
        }

        if(i <= m) l -> update(i);
        else r -> update(i);
        v = max(l -> v, r -> v);
    }
}*root;

void dfs(int i, int p){
    parent[i] = p;

    pre[i] = cont;
    cont++;

    for(int j : adjlst[i]){
        if(j == p) continue;
        dfs(j,i);
    }

    post[i] = cont - 1;
}

long long int solve(int i, int l, int r){

    long long int ans = 0;

    for(int j : adjlst[i]){
        if(j == parent[i]) continue;
        if(done[j]) continue;

        ans += (root -> query(pre[j],post[j])).first + lst[i];
    }

    root -> update(pre[i]);

    if(parent[i] != -1 && !done[parent[i]]){
        ans += (root -> query(l,r)).first + lst[i];
    }

    done[i] = true;

    for(int j : adjlst[i]){
        if(j == parent[i]) continue;
        if(done[j]) continue;

        int k = (root -> query(pre[j],post[j])).second;

        ans += solve(k,pre[j],post[j]);
    }

    if(parent[i] != -1 && !done[parent[i]]){
        int k = (root -> query(l,r)).second;
        ans += solve(k,l,r);
    }

    return ans;
}

int main(){

    scanf(" %d",&N);

    for(int i = 1; i <= N; i++){
        scanf(" %d",&lst[i]);
        done[i] = false;
    }

    for(int i = 0; i < N - 1; i++){
        scanf(" %d",&u);
        scanf(" %d",&v);

        adjlst[u].push_back(v);
        adjlst[v].push_back(u);
    }

    dfs(1,-1);

    for(int i = 1; i <= N; i++){
        invlst[pre[i]] = i;
    }

    root = new node(0,N-1);

    printf("%lld",solve( (root -> query(0,N-1) ).second , 0, N - 1) );

}

컴파일 시 표준 에러 (stderr) 메시지

sjekira.cpp: In function 'int main()':
sjekira.cpp:110:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  110 |     scanf(" %d",&N);
      |     ~~~~~^~~~~~~~~~
sjekira.cpp:113:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  113 |         scanf(" %d",&lst[i]);
      |         ~~~~~^~~~~~~~~~~~~~~
sjekira.cpp:118:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  118 |         scanf(" %d",&u);
      |         ~~~~~^~~~~~~~~~
sjekira.cpp:119:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  119 |         scanf(" %d",&v);
      |         ~~~~~^~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 30
• Subtask 4: 0 / 60