제출 #1148581

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1148581		arkanefury	Valley (BOI19_valley)	C++20	59 / 100	177 ms	35784 KiB

valley

#include <bits/stdc++.h>  
#define pb push_back  
using namespace std; 
#define F first
#define S second
#define int long long
#define FOR(x, n, m, d) for(int x = n; x <= m; x += d)  
#define FORR(x, n, m, d) for(int x = n; x >= m; x -= d)  
#define nikita ios_base::sync_with_stdio(0), cin.tie(0);  
const int N = 1e5+150;  
int n,m,k,tt,ans,l, r, x, y, cnt, ko = 0; 
int b[N],a[N], sum, root[N], block =  620, d[N], c[N], up[N][21], par[N];
string s[N], str;
vector<pair<int, int>>g[N];
bool f = 0;
map<pair<int, int>, int>mp;
void dfs(int v, int p = 0, int sum = 0){
    if(cnt == v){f = 1;return;}
    if(c[v]){
        ko = min(ko, sum);
    }
    for(auto i : g[v]){
        if(i.F != p && mp[{v, i.F}] == 0){
            dfs(i.F, v, sum + i.S);
        }
    }
}
int lca(int x, int y){
    if(d[x] <= d[y])swap(x, y);
    FORR(i, 20, 0, 1)if(d[y] <= d[up[x][i]])x = up[x][i];
    if(x == y)return y;
    FORR(i, 20, 0, 1)if(up[x][i] != up[y][i])x = up[x][i], y = up[y][i];
    return up[x][0];
}
void sol(int v, int p = 0){
    d[v] = d[p] + 1;
    par[v] = p;
    for(auto i : g[v]){
        if(p != i.F && v != i.F)sol(i.F, v);
    }
}
void solve(){
    nikita
    cin >> n >> m >> k >> cnt;
    FOR(i, 1, n-1, 1){
        cin >> a[i] >> b[i] >> r;
        x = a[i], y = b[i];
        g[x].pb({y, r}), g[y].pb({x, r});
    }
    FOR(i, 1, m, 1)cin >> d[i], c[d[i]] = 1;
    if(n > 1000 || m > 1000){
        sol(1);
        FOR(i, 1,n, 1)up[i][0] = par[i];
        FOR(i, 1, 20, 1){
            FOR(j,1,n,1)up[j][i] = up[up[j][i-1]][i-1];
        }
        FOR(i, 1, k, 1){
            cin >> x >> y;
            int lp = lca(y, cnt);
            if(a[x] == lca(a[x], y) && b[x] == lca(b[x], y) && min(d[a[x]], d[b[x]]) >= d[lp] || a[x] == lca(a[x], cnt) && b[x] == lca(b[x], cnt) && d[lp] <= min(d[a[x]], d[b[x]])){
                cout << "0\n";
            }
            else cout << "escaped\n";
        }
        return;
    }
    FOR(i, 1, k, 1){
        f = 0;
        ko = 1e18;
        cin >> x >> y;
        mp[{a[x], b[x]}] = 1, mp[{b[x], a[x]}] = 1;
        dfs(y);
        mp[{a[x], b[x]}] = mp[{b[x], a[x]}] = 0;
        if(f)cout << "escaped\n";
        else if(ko != 1e18)cout << ko << '\n';
        else cout << "oo\n";
    }
}
signed main()  
{  
    nikita  
    tt = 1;  
    if(!tt)cin >> tt;  
    FOR(i, 1, tt, 1){  
    solve();  
    }  
}

• Subtask 1: 9 / 9
• Subtask 2: 27 / 27
• Subtask 3: 23 / 23
• Subtask 4: 0 / 41