Submission #875760

#	Time	Username	Problem	Language	Result	Execution time	Memory
875760		dimashhh	Jail (JOI22_jail)	C++17	72 / 100	4215 ms	1048576 KiB

jail

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 2e5 + 10, MOD = 998244353;

vector<int> g[N], x[N], gt[N];
int timer = 0, tin[N], tout[N], n, m, s[N], t[N], pp[N], val[N], used[N], val1[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 res = 1;
void dfs1(int v){
    used[v] = 1;
    for(int to:gt[v]){
        if(used[to] == 1){
            res =0 ;
        }
        if(!used[to]){
            dfs1(to);
        }
    }
    used[v] = 2;
}
void test()
{
    res = 1;
    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);
    }
    dfs(1);
    cin >> m;
    for(int i = 1;i <= n;i++){
        val1[i] = val[i] = 0;
    }
    for(int i = 1;i <= m;i++){
        gt[i].clear();
    }
    for (int i = 1; i <= m; ++i)
    {
        cin >> s[i] >> t[i];
        used[i] = 0;
        val[s[i]] = i;
        val1[t[i]] = i;
    }
    for(int i = 1;i <= m;i++){
        for(int j:path(s[i],t[i])){
            int x = val[j];
            // cout << j << ' ';
            if(x && x != i){
                gt[i].push_back(x);
                // cout << i << ' ' << x << '\n';
            }
            x = val1[j];
            if(x && x != i){
                gt[x].push_back(i);
                // cout << i << ' ' << x << '\n';
            }
        }
        cout << '\n';
    }
    for(int i = 1;i <= m;i++){
        if(!used[i] && res){
            dfs1(i);
        }
    }
    cout << (res ? "Yes\n" : "No\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:101:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  101 | main()
      | ^~~~

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