#543998 (C++14) No.1212 Second Path

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結果

問題	No.1212 Second Path
コンテスト
ユーザー	heno239
提出日時	2020-08-30 14:36:58
言語	C++14 (gcc 13.3.0 + boost 1.87.0)
結果	AC
実行時間	566 ms / 3,000 ms
コード長	6,395 bytes
コンパイル時間	1,757 ms
コンパイル使用メモリ	129,260 KB
実行使用メモリ	85,888 KB
最終ジャッジ日時	2024-11-15 07:47:48
合計ジャッジ時間	19,491 ms
ジャッジサーバーID （参考情報）	judge1 / judge5

このコードへのチャレンジ
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ファイルパターン	結果
sample	AC * 3
other	AC * 45

権限があれば一括ダウンロードができます

ソースコード

raw source code

#include<iostream>
#include<string>
#include<cstdio>
#include<vector>
#include<cmath>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<queue>
#include<ciso646>
#include<random>
#include<map>
#include<set>
#include<bitset>
#include<stack>
#include<unordered_map>
#include<utility>
#include<cassert>
#include<complex>
#include<numeric>
#include<array>
using namespace std;

//#define int long long
typedef long long ll;

typedef unsigned long long ul;
typedef unsigned int ui;
constexpr ll mod = 1000000007;
const ll INF = mod * mod;
typedef pair<int, int>P;
#define stop char nyaa;cin>>nyaa;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
#define all(v) (v).begin(),(v).end()
typedef pair<ll, ll> LP;
typedef long double ld;
typedef pair<ld, ld> LDP;
const ld eps = 1e-12;
const ld pi = acosl(-1.0);

ll mod_pow(ll x, ll n, ll m = mod) {
	ll res = 1;
	while (n) {
		if (n & 1)res = res * x % m;
		x = x * x % m; n >>= 1;
	}
	return res;
}
struct modint {
	ll n;
	modint() :n(0) { ; }
	modint(ll m) :n(m) {
		if (n >= mod)n %= mod;
		else if (n < 0)n = (n % mod + mod) % mod;
	}
	operator int() { return n; }
};
bool operator==(modint a, modint b) { return a.n == b.n; }
modint operator+=(modint& a, modint b) { a.n += b.n; if (a.n >= mod)a.n -= mod; return a; }
modint operator-=(modint& a, modint b) { a.n -= b.n; if (a.n < 0)a.n += mod; return a; }
modint operator*=(modint& a, modint b) { a.n = ((ll)a.n * b.n) % mod; return a; }
modint operator+(modint a, modint b) { return a += b; }
modint operator-(modint a, modint b) { return a -= b; }
modint operator*(modint a, modint b) { return a *= b; }
modint operator^(modint a, ll n) {
	if (n == 0)return modint(1);
	modint res = (a * a) ^ (n / 2);
	if (n % 2)res = res * a;
	return res;
}

ll inv(ll a, ll p) {
	return (a == 1 ? 1 : (1 - p * inv(p % a, a)) / a + p);
}
modint operator/(modint a, modint b) { return a * modint(inv(b, mod)); }

const int max_n = 1 << 19;
modint fact[max_n], factinv[max_n];
void init_f() {
	fact[0] = modint(1);
	for (int i = 0; i < max_n - 1; i++) {
		fact[i + 1] = fact[i] * modint(i + 1);
	}
	factinv[max_n - 1] = modint(1) / fact[max_n - 1];
	for (int i = max_n - 2; i >= 0; i--) {
		factinv[i] = factinv[i + 1] * modint(i + 1);
	}
}
modint comb(int a, int b) {
	if (a < 0 || b < 0 || a < b)return 0;
	return fact[a] * factinv[b] * factinv[a - b];
}

int gcd(int a, int b) {
	if (a < b)swap(a, b);
	while (b) {
		int r = a % b; a = b; b = r;
	}
	return a;
}

int depth[1 << 17];
int par[1 << 17][17];
ll parcost[1 << 17][17];
int specost[1 << 17][17];
vector<int> costs[1 << 17];
vector<int> ids[1 << 17];
multiset<int> st[1 << 17];

struct edge {
	int to, cost;
};
bool operator<(const edge& a, const edge& b) {
	if (a.to != b.to)return a.to < b.to;
	return a.cost < b.cost;
}

int lca(int a, int b) {
	if (depth[a] > depth[b])swap(a, b);
	//cout << "bef " << a << " " << b << "\n";
	int dif = depth[b] - depth[a];
	//cout << dif << "\n";
	rep(j, 17)if (dif & (1 << j)) {
		b = par[b][j];
	}
	//cout << "aft " << a << " " << b << "\n";
	if (a == b)return a;
	else {
		per(j, 17) {
			if (par[a][j] != par[b][j]) {
				a = par[a][j], b = par[b][j];
			}
		}
		return par[a][0];
	}
}

int calcspe(int x, int d) {
	int res = mod;
	rep(j, 17) {
		if (d & (1 << j)) {
			res = min(res, specost[x][j]);
			x = par[x][j];
		}
	}
	return res;
}
int calcloc(int x, int d) {
	rep(j, 17) {
		if (d & (1 << j)) {
			x = par[x][j];
		}
	}
	return x;
}
ll calcsum(int x, int d) {
	ll res = 0;
	rep(j, 17) {
		if (d & (1 << j)) {
			res += parcost[x][j];
			x = par[x][j];
		}
	}
	return res;
}
void solve() {
	int n; cin >> n;
	vector<vector<edge>> G(n);
	rep(i, n - 1) {
		int a, b, c; cin >> a >> b >> c; a--; b--;
		G[a].push_back({ b,c });
		G[b].push_back({ a,c });
	}
	rep(i, n)sort(all(G[i]));
	function<void(int,int)> dfs = [&](int id, int fr) {
		par[id][0] = fr;
		for (edge e : G[id])if (e.to != fr) {
			parcost[e.to][0] = e.cost;
			depth[e.to] = depth[id] + 1;
			dfs(e.to, id);
			costs[id].push_back(e.cost);
			ids[id].push_back(e.to);
			st[id].insert(e.cost);
		}
		st[id].insert(mod);
		for (edge e : G[id])if (e.to != fr) {
			auto itr = st[id].begin();
			if ((*st[id].begin()) == e.cost)itr++;
			specost[e.to][0] = (*itr);
		}
	}; dfs(0, -1);
	rep(j, 16)rep(i, n) {
		if (par[i][j] >= 0) {
			par[i][j + 1] = par[par[i][j]][j];
			parcost[i][j + 1] =parcost[i][j]+parcost[par[i][j]][j];
			specost[i][j + 1] = min(specost[i][j], specost[par[i][j]][j]);
		}
		else {
			par[i][j + 1] = -1;
		}
	}
	int q; cin >> q;
	rep(i, q) {
		int x, y; cin >> x >> y; x--; y--;
		int l = lca(x, y); //cout << "ai " << l << "\n";
		int mi = mod;
		if (depth[x]-depth[l]>0) {
			mi = min(mi, calcspe(x, depth[x] - depth[l] -1));
		}
		if (depth[y]-depth[l]>0) {
			mi = min(mi, calcspe(y, depth[y] - depth[l] - 1));
		}
		if (y == l)swap(x, y);
		if (x == l) {
			int py = calcloc(y, depth[y] - depth[l] - 1);
			
			py = lower_bound(all(ids[l]), py) - ids[l].begin();
			int val = costs[l][py];
			auto itr = st[l].begin();
			if (*itr == val)itr++;
			mi = min(mi, *itr);

			mi = min(mi, *st[y].begin());
		}
		else {
			mi = min(mi, *st[x].begin());
			mi = min(mi, *st[y].begin());
			int px = calcloc(x, depth[x] - depth[l] - 1);
			int py = calcloc(y, depth[y] - depth[l] - 1);
			px = lower_bound(all(ids[l]), px) - ids[l].begin();
			py = lower_bound(all(ids[l]), py) - ids[l].begin();
			int val[2] = { costs[l][px],costs[l][py] };
			if (val[0] > val[1])swap(val[0], val[1]);
			auto itr = st[l].begin();
			rep(aa, 2) {
				if (*itr == val[aa]) {
					itr++;
				}
				else break;
			}
			mi = min(mi, (*itr));
		}
		if (par[l][0] >= 0) {
			mi = min(mi, (int)parcost[l][0]);
		}
		if (mi == mod) {
			cout << -1 << "\n";
		}
		else {
			//cout << mi<<" hoge\n";
			ll ans = 2*mi;
			ans += calcsum(x, depth[x] - depth[l]);
			//cout << x << " " << depth[x] - depth[l] << " " << calcsum(x,depth[x] - depth[l])<<"\n";
			ans += calcsum(y, depth[y] - depth[l]);
			cout << ans << "\n";
		}

	}
}

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	//cout << fixed << setprecision(15);
	//init_f(); 
	//init();
	//expr();
	//int t; cin >> t; rep(i, t)
	solve();
	return 0;
}

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結果

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