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Submission #328633

# Submission time Handle Problem Language Result Execution time Memory
328633 2020-11-17T11:18:58 Z soroush Valley (BOI19_valley) C++14
100 / 100
 314 ms 66796 KB 
//*
#pragma GCC optimize("O2")
//#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
//#pragma GCC target("avx,avx2,sse,sse2,fma,tune=native")
//*/
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<ll  ,ll > pii;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const ll maxn  = 1e5 + 100;
const ll mod =1e9+7;
const ld PI = acos((ld)-1);

#define pb push_back
#define endl '\n'
#define dokme(x) cout << x , exit(0)
#define migmig ios::sync_with_stdio(false),cin.tie(0),cout.tie(0)
#define ms(x , y) memset(x , y , sizeof x)
ll pw(ll a, ll b, ll md = mod){ll res = 1;while(b){if(b&1){res=(a*res)%md;}a=(a*a)%md;b>>=1;}return(res);}

int n , q , s , ex;
bool shop[maxn];

pii e[maxn];
ll w[maxn];

int par[maxn][23];
vector < pii > adj[maxn];
int h[maxn];
int l[maxn] , r[maxn] , t = 0;
ll H[maxn];
int ord[maxn];

void dfs(int v){
	r[v] = l[v] = ++t;
	ord[t] = v;
    for (auto uw : adj[v]){
		auto u = uw.first;
		auto w = uw.second;
        if(u!=par[v][0]){
            par[u][0] = v;
            h[u] = h[v]+1;
            H[u] = H[v] + w;
            dfs(u);
            r[v] = r[u];
        }
	}
}

int lca(int u , int v){
    if(h[u] > h[v]){
        swap(u , v);
    }
    for (int i = 20 ; i >= 0 ; i --){
        if(par[v][i] and h[par[v][i]]>=h[u]){
            v = par[v][i];
        }
    }
    if(v == u){
        return(v);
    }
    for (int i = 20 ; i >= 0 ; i --){
        if(par[v][i] != par[u][i]){
            v = par[v][i] , u = par[u][i];
        }
    }
    return(par[v][0]);
}

void init(){
	dfs(ex);
    for (int j = 1; j <= 20 ; j ++){
        for (int i = 1 ; i <= n ; i ++){
            par[i][j] = par[par[i][j - 1]][j - 1];
        }
    }
}

ll dist(int u , int v){
	return(H[u] + H[v] - 2*H[lca(u, v)]);
}

ll f[maxn][23];
ll val[maxn][23];

ll mn(ll l , ll r){
	ll cur = l;
	ll ans = val[l][0];
	for(int i = 20 ; i >= 0 ; i --){
		if(cur + (1 << i) > r)continue;
		ans = min(ans , val[cur][i]);
		cur+=(1 << i);
		ans = min(ans , val[cur][0]);
	}
	return(ans);
}

int32_t main(){
    migmig;
	cin >> n >> s >> q >> ex;
	for(int i = 1 ; i < n ; i ++)
		cin >> e[i].first >> e[i].second >> w[i],
		adj[e[i].first].pb({e[i].second , w[i]}),
		adj[e[i].second].pb({e[i].first , w[i]});
	for(int i = 0 ; i < s ; i ++){
		int x;
		cin >> x;
		shop[x] = 1;
	}
	init();
	h[0] = -1;
	for(int i = 1 ; i <= n ; i ++){
		if(shop[i])val[l[i]][0] = H[i];
		else val[l[i]][0] = 1e18;
	}
	for(int j = 0 ; j < 20 ; j ++){
		for(int i = 1 ; i <= n ; i ++){
			if(i + (1 << j) > n)continue;
			val[i][j+1] = min(val[i][j] , val[i + (1 << j)][j]);
		}
	}
	for(int i = 1 ; i <= n ; i ++){
		if(mn(l[i] , r[i]) == 1e18)
			f[i][0] = 1e18;
		else
			f[i][0] = mn(l[i] , r[i]) - 2LL*H[i];
	}
	for(int j = 1 ; j <= 20 ; j ++)
		for(int i = 1 ; i <= n ; i ++)
			f[i][j] = min(f[i][j-1] ,f[par[i][j-1]][j-1]);
	while(q -- ){
		int i , V;
		cin >> i >> V;
		auto u = e[i].first;
		auto v = e[i].second;
		if(h[u] < h[v])swap(u , v);
		if(l[u] <= l[V] and l[V] <= r[u]){
			if(f[u][0] == 1e18){
				cout << "oo" << endl;
			}
			else{
				int cur = V;
				ll ans = 1e18;
				for(int i = 20 ; i >= 0 ; i --){
					if(h[par[cur][i]] < h[u] )continue;
					ans = min(ans , f[cur][i]);
					cur = par[cur][i];
					ans = min(ans , f[cur][0]);
				}
				ans = min(ans , f[cur][0]);
				cout << ans + H[V] << endl;
			}
		}
		else{
			cout << "escaped" << endl;
		}
	}
    return(0);
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 2924 KB Output is correct
2 Correct 5 ms 2924 KB Output is correct
3 Correct 6 ms 2924 KB Output is correct
4 Correct 5 ms 2924 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 2924 KB Output is correct
2 Correct 5 ms 2924 KB Output is correct
3 Correct 6 ms 2924 KB Output is correct
4 Correct 5 ms 2924 KB Output is correct
5 Correct 3 ms 3308 KB Output is correct
6 Correct 3 ms 3308 KB Output is correct
7 Correct 4 ms 3436 KB Output is correct
8 Correct 3 ms 3308 KB Output is correct
9 Correct 3 ms 3308 KB Output is correct
10 Correct 3 ms 3308 KB Output is correct
11 Correct 3 ms 3308 KB Output is correct
12 Correct 3 ms 3308 KB Output is correct
13 Correct 3 ms 3436 KB Output is correct
14 Correct 3 ms 3436 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 248 ms 62316 KB Output is correct
2 Correct 249 ms 62060 KB Output is correct
3 Correct 257 ms 62188 KB Output is correct
4 Correct 282 ms 64364 KB Output is correct
5 Correct 257 ms 64236 KB Output is correct
6 Correct 314 ms 66356 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 2924 KB Output is correct
2 Correct 5 ms 2924 KB Output is correct
3 Correct 6 ms 2924 KB Output is correct
4 Correct 5 ms 2924 KB Output is correct
5 Correct 3 ms 3308 KB Output is correct
6 Correct 3 ms 3308 KB Output is correct
7 Correct 4 ms 3436 KB Output is correct
8 Correct 3 ms 3308 KB Output is correct
9 Correct 3 ms 3308 KB Output is correct
10 Correct 3 ms 3308 KB Output is correct
11 Correct 3 ms 3308 KB Output is correct
12 Correct 3 ms 3308 KB Output is correct
13 Correct 3 ms 3436 KB Output is correct
14 Correct 3 ms 3436 KB Output is correct
15 Correct 248 ms 62316 KB Output is correct
16 Correct 249 ms 62060 KB Output is correct
17 Correct 257 ms 62188 KB Output is correct
18 Correct 282 ms 64364 KB Output is correct
19 Correct 257 ms 64236 KB Output is correct
20 Correct 314 ms 66356 KB Output is correct
21 Correct 220 ms 61804 KB Output is correct
22 Correct 230 ms 61420 KB Output is correct
23 Correct 242 ms 61548 KB Output is correct
24 Correct 255 ms 64108 KB Output is correct
25 Correct 278 ms 66796 KB Output is correct
26 Correct 221 ms 61804 KB Output is correct
27 Correct 231 ms 61420 KB Output is correct
28 Correct 244 ms 61784 KB Output is correct
29 Correct 261 ms 63216 KB Output is correct
30 Correct 281 ms 64748 KB Output is correct
31 Correct 218 ms 61676 KB Output is correct
32 Correct 236 ms 61548 KB Output is correct
33 Correct 247 ms 61932 KB Output is correct
34 Correct 266 ms 63852 KB Output is correct
35 Correct 277 ms 66668 KB Output is correct
36 Correct 253 ms 63724 KB Output is correct