제출 #463804

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
463804		ezdp	경주 (Race) (IOI11_race)	C++14	0 / 100	4 ms	2124 KiB

race

#pragma GCC target ("sse4")
#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")

#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>

#define endl '\n'
#define pb push_back
#define fr first
#define sc second
#define ll long long int
#define ld long double
#define bit(idx) idx&(-idx)
#define bin(x) bitset<32>(x).to_string()
#define all(A) A.begin(), A.end()
#define de(x) cout << #x << " = " << x << endl;

using namespace std;
using namespace __gnu_pbds;

template<class T> using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<class T> using matrix = vector<vector<T>>;
/// find_by_order(x) -> x-th element in the set
/// order_of_key(x)  -> how many elements are smaller than x
/// insert(x)		 -> inserts x into the set

const ll MAXN = 2e5 + 5;
const ll MAXL = 18;
const ll INF = 1e16 + 16;

ll n, k, up[MAXN][MAXL], len[MAXN], depth[MAXN], tin[MAXN], tout[MAXN], T, ans = INF, root = 1, used[MAXN], sz[MAXN], mn[MAXN];
matrix<pair<ll, ll>> G;
matrix<ll> C;
vector<pair<ll, ll>> upd;
set<ll> rem;

void dfs_lca(ll u = 1, ll p = 1, ll d = 0, ll L = 0){
	tin[u] = ++ T;
	depth[u] = d;
	len[u] = L;
	
	up[u][0] = p; for(int i = 1; i < MAXL; i ++) up[u][i] = up[up[u][i - 1]][i - 1];
	
	for(auto [v, l] : G[u]){
		if(v != p){
			dfs_lca(v, u, d + 1, L + l);
		}
	}
	
	tout[u] = ++ T;
}

bool is_ancestor(ll u, ll v){
	return (tin[u] <= tin[v] && tout[v] <= tout[u]);
}

ll lca(ll u, ll v){
	if(is_ancestor(u, v))
		return u;
	if(is_ancestor(v, u))
		return v;
	for(int i = MAXL - 1; i >= 0; i --){
		if(!is_ancestor(up[u][i], v)){
			u = up[u][i];
		}
	}
	return up[u][0];
}

pair<ll, ll> dist(ll u, ll v){
	ll lc = lca(u, v);
	return {depth[u] + depth[v] - 2 * depth[lc], len[u] + len[v] - 2 * len[lc]};
}

ll find_size(ll u, ll p = -1){
	if(used[u]) return 0;
	sz[u] = 1;
	for(auto [v, l] : G[u]){
		if(v != p && !used[v]){
			sz[u] += find_size(v, u);
		}
	}
	return sz[u];
}

ll find_centroid(ll u, ll p, ll cn){
	for(auto [v, l] : G[u]){
		if(v != p && !used[v] && sz[v] > cn / 2){
			return find_centroid(v, u, cn);
		}
	}
	return u;
}

void init_centroid(ll u = 1, ll p = -1){
	find_size(u);
	ll c = find_centroid(u, -1, sz[u]);
	used[c] = true;
	if(p == -1){ root = c; }
	else{ C[c].pb(p); C[p].pb(c); }
	for(auto [v, l] : G[c]){
		if(!used[v]){
			init_centroid(v, c);
		}
	}
}

void dfs2(ll u, ll p, ll c){
	auto tmp = dist(u, c);
	if(tmp.sc <= k){
		ans = min(ans, mn[k - tmp.sc] + tmp.fr);
		upd.pb({tmp.sc, tmp.fr});
		rem.insert(tmp.sc);
	}
	for(auto v : C[u]){
		if(v != p){
			dfs2(v, u, c);
		}
	}
}

void dfs1(ll u, ll p){
	mn[0] = 0;
	for(auto v : C[u]){
		dfs2(v, u, u);
		for(auto [x, v] : upd) mn[x] = min(mn[x], v);
	}
	for(auto x : rem) mn[x] = INF;
	for(auto v : C[u]){
		if(v != p){
			dfs1(v, u);
		}
	}
}

int best_path(int N, int K, int h[][2], int L[]){
	n = N; k = K;
	C = matrix<ll>(n + 1);
	G = matrix<pair<ll, ll>>(n + 1);
	for(int i = 0; i < n - 1; i ++){ G[h[i][0]].pb({h[i][1], L[i]}); G[h[i][1]].pb({h[i][0], L[i]}); }
	for(int i = 0; i < MAXN; i ++) mn[i] = INF;
	
	dfs_lca();
	init_centroid();
	dfs1(root, root);
	
	return (ans == INF ? -1 : ans);
}

컴파일 시 표준 에러 (stderr) 메시지

race.cpp:3: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    3 | #pragma GCC optimization ("O3")
      | 
race.cpp:4: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    4 | #pragma GCC optimization ("unroll-loops")
      | 
race.cpp: In function 'void dfs_lca(long long int, long long int, long long int, long long int)':
race.cpp:46:11: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   46 |  for(auto [v, l] : G[u]){
      |           ^
race.cpp: In function 'long long int find_size(long long int, long long int)':
race.cpp:80:11: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   80 |  for(auto [v, l] : G[u]){
      |           ^
race.cpp: In function 'long long int find_centroid(long long int, long long int, long long int)':
race.cpp:89:11: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   89 |  for(auto [v, l] : G[u]){
      |           ^
race.cpp: In function 'void init_centroid(long long int, long long int)':
race.cpp:103:11: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  103 |  for(auto [v, l] : G[c]){
      |           ^
race.cpp: In function 'void dfs1(long long int, long long int)':
race.cpp:128:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  128 |   for(auto [x, v] : upd) mn[x] = min(mn[x], v);
      |            ^

• Subtask 1: 0 / 9
• Subtask 2: 0 / 12
• Subtask 3: 0 / 22
• Subtask 4: 0 / 57