Submission #875653

#	Time	Username	Problem	Language	Result	Execution time	Memory
875653		dimashhh	Jail (JOI22_jail)	C++17	49 / 100	5096 ms	283616 KiB

jail

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 5e5 + 10, MOD = 998244353;

vector<int> g[N],x[N];
int timer = 0,tin[N],tout[N],n,m,s[N],t[N],blocked[N],c[N],pp[N];
bool used[N];
void dfs(int v,int pr = 1){
    tin[v] = ++timer;
    pp[v] = pr;
    for(int to:g[v]){
        if(to == pr) continue;
        dfs(to,v);
    }
    tout[v] = ++timer;
}
bool is(int v,int u){
    return (tin[v] <= tin[u] && tout[v] >= tout[u]);
}
vector<int> path(int v,int u){
    vector<int> p(1,v);
    while(!is(v,u)){
        v = pp[v];
        p.push_back(v);
    }
    while(!is(u,v)){
        p.push_back(u);
        u = pp[u];
    }
    return p;
}
bool can(int i){
    for(int j:x[i]){
        if(j != s[i] && used[j]) return false;
    }
    if(c[t[i]] > 1) return false;
    return true;
}
void test(){
    timer =0 ;
    cin >> n;
    for(int i = 1;i <= n;i++)
        g[i].clear();
    for(int i = 1;i <= n - 1;i++){
        int x,y;
        cin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
        used[x] = used[y] = c[x] = c[y] = 0;
    }
    dfs(1);
    cin >> m;
    for(int i = 1;i <= m;i++){
        blocked[i] = 0;
    }
    for(int i = 1;i <= m;++i){
        cin >> s[i] >> t[i];
        used[s[i]] = 1;

        x[i] = path(s[i],t[i]);
        for(auto j:x[i]){
            c[j]++;
        }
    }
    for(int i = 1;i <= m;i++){
        bool ok = false;
        for(int j = 1;j <= m;j++){
            if(blocked[j] || !can(j)) continue;
            blocked[j] = 1;
            for(auto k:x[j]){
                c[k]--;
            }
            ok = 1;
            used[s[j]] = 0;
            used[t[j]] = 1;
            break;
        }
        if(!ok){
            cout << "No\n";
            return;
        }
    }
    cout << "Yes\n";
}
main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int T = 1;
    cin >> T;
    for (int i = 1; i <= T; i++)
    {
        test();
    }
}

Compilation message (stderr)

jail.cpp: In function 'void test()':
jail.cpp:50:34: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   50 |         used[x] = used[y] = c[x] = c[y] = 0;
      |                             ~~~~~^~~~~~~~~~
jail.cpp: At global scope:
jail.cpp:86:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   86 | main()
      | ^~~~

• Subtask 1: 0 / 5
• Subtask 2: 5 / 5
• Subtask 3: 16 / 16
• Subtask 4: 28 / 28
• Subtask 5: 0 / 12
• Subtask 6: 0 / 11
• Subtask 7: 0 / 23