제출 #701483

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
701483		sugartheanh	동기화 (JOI13_synchronization)	C++14	0 / 100	5 ms	5076 KiB

synchronization

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

#define dbg(x) cerr << #x << ": " << x << endl;
#define ii pair<int,int>
#define fi first
#define se second
const int MOD = 1e9 + 7;
const int N = 2e5 + 5;
int n,m,q,first[N],last[N],d[N],root;
vector<ii>p[N];
bool on[N];
void dfs(int x,int u,int R)
{
    for(auto v : p[u])
    {
        if(v.fi == x)
            continue;
        if(first[v.se] < R)
        {
            dfs(u,v.fi,min(R,last[v.se]));
            d[u] += d[v.fi];
        }
    }
}
int main() {
    freopen("NEW.INP","r",stdin);
    freopen("NEW.OUT","w",stdout);
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cin>>n>>m>>q;
    for(int i = 1;i < n;i++)
    {
        int u,v;
        cin>>u>>v;
        p[u].push_back(ii(v,i));
        p[v].push_back(ii(u,i));
    }
    for(int i = 1;i <= n;i++)
        first[i] = 1e9;
    for(int i = 1;i <= m;i++)
    {
        int x;
        cin>>x;
        if(!on[x])
            first[x] = min(first[x], i);
        else
            last[x] = max(last[x], i);
        on[x] ^= 1;
    }
    for(int i = 1;i < n;i++)
    {
        if(first[i] < 1e9 && last[i] == 0)
            last[i] = 1e9;
//        cout<<first[i]<<' '<<last[i]<<'\n';
    }
//    cout<<'\n';
    while(q--)
    {
        cin>>root;
        for(int i = 1;i <= n;i++)
            d[i] = 1;
        dfs(0,root,1e9);
//        for(int i = 1;i <= n;i++)
//            cout<<i<<' '<<d[i]<<'\n';
//        cout<<'\n';
        cout<<d[root]<<'\n';
    }
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

synchronization.cpp: In function 'int main()':
synchronization.cpp:27:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |     freopen("NEW.INP","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
synchronization.cpp:28:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |     freopen("NEW.OUT","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 20
• Subtask 3: 0 / 10
• Subtask 4: 0 / 20
• Subtask 5: 0 / 40