제출 #1162657

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1162657		SmuggingSpun	Construction of Highway (JOI18_construction)	C++20	16 / 100	227 ms	1064 KiB

construction

#include<bits/stdc++.h>
#define taskname "A"
using namespace std;
int n;
namespace sub12{
    void solve(){
        vector<int>c(n + 1), _c(n);
        for(int i = 1; i <= n; i++){
            cin >> c[i];
            _c[i - 1] = c[i]; 
        }
        sort(_c.begin(), _c.end());
        for(int i = 1; i <= n; i++){
            c[i] = lower_bound(_c.begin(), _c.end(), c[i]) - _c.begin() + 1;
        }
        vector<int>bit(n + 1);
        auto update = [&] (int p){
            for(; p <= n; p += p & -p){
                bit[p]++;
            }
        };
        auto get = [&] (int p){
            int ans = 0;
            for(; p > 0; p -= p & -p){
                ans += bit[p];
            }
            return ans;
        };
        int a, b, ans;
        vector<vector<int>>g(n + 1);
        vector<int>path;
        function<void(int, int)>dfs;
        dfs = [&] (int s, int p){
            path.emplace_back(s);
            for(int& d : g[s]){
                if(d != p){
                    dfs(d, s);
                }
            }
            if(s == a){
                for(int i = int(path.size()) - 1; i > -1; i--){
                    ans += get(c[path[i]] - 1);
                    update(c[path[i]]);
                }
                for(int& i : path){
                    c[i] = c[b];
                }
            }
            path.pop_back();
        };
        for(int _ = 1; _ < n; _++){
            cin >> a >> b;
            fill(bit.begin(), bit.end(), ans = 0);
            dfs(1, -1);
            cout << ans << "\n";
            g[a].emplace_back(b);
            g[b].emplace_back(a);
        }
    }
}
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
	}
    cin >> n;
    if(n <= 4000){
        sub12::solve();
    }
}

컴파일 시 표준 에러 (stderr) 메시지

construction.cpp: In function 'int main()':
construction.cpp:64:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |                 freopen(taskname".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 9 / 9
• Subtask 3: 0 / 84