Submission #130646

#	Time	Username	Problem	Language	Result	Execution time	Memory
130646		abacaba	Factories (JOI14_factories)	C++14	0 / 100	55 ms	28412 KiB

factories

#include <bits/stdc++.h>
using namespace std;

#define pb push_back
#define ll long long

const int l = 21;
const ll inf = 2e15;
const int MAX_N = 5e5 + 15;

int n, m, sz[MAX_N], up[MAX_N][l], tin[MAX_N], tout[MAX_N], last;
ll minn[MAX_N];
vector <int> g[MAX_N], d[MAX_N];
int pCentroid[MAX_N];
ll dist[MAX_N];
bool deleted[MAX_N];

void start(int v, int p) {
	tin[v] = ++last;
	up[v][0] = p;
	for(int i = 1; i < l; ++i)
		up[v][i] = up[up[v][i-1]][i-1];
	for(int i = 0; i < g[v].size(); ++i)
		if(g[v][i] != p) {
			dist[g[v][i]] = dist[v] + d[v][i];
			start(g[v][i], v);
		}
	tout[v] = ++last;
}

inline bool upper(int a, int b) {
	return tin[a] <= tin[b] && tout[a] >= tout[b];
}

int lca(int a, int b) {
	if(upper(a, b))
		return a;
	if(upper(b, a))
		return b;
	for(int i = l - 1; i >= 0; --i)
		if(!upper(up[a][i], b))
			a = up[a][i];
	return up[a][0];
}

void build(int v, int p = -1) {
	sz[v] = 1;
	for(auto to : g[v])
		if(to != p && !deleted[to]) {
			build(to, v);
			sz[v] += sz[to];
		}
}
 
int centroid(int v, int p, int n) {
	for(auto to : g[v])
		if(!deleted[to] && to != p && sz[to] > n / 2)
			return centroid(to, v, n);
	return v;
}

void process(int node, int p = -1) {
	build(node, -1);
	int center = centroid(node, node, sz[node]);
	deleted[center] = true;
	if(p == -1)
		p = center;
	pCentroid[center] = p;
	for(int to : g[center])
		if(!deleted[to])
			process(to, center);
}

void Init(int N, int A[], int B[], int D[]) {
	n = N;
	for(int i = 0; i < n; ++i) {
		++A[i];
		++B[i];
		g[A[i]].pb(B[i]);
		d[A[i]].pb(D[i]);
 
		g[B[i]].pb(A[i]);
		d[B[i]].pb(D[i]);
	}
	fill(minn, minn + MAX_N, inf);
	start(1, 1);
	process(1);
}

long long Query(int S, int X[], int T, int Y[]) {
	ll ans = inf;
	for(int i = 0; i < S; ++i)
		++X[i];
	for(int i = 0; i < T; ++i)
		++Y[i];
	for(int i = 0; i < S; ++i) {
		int v = X[i] + 1;
		while(1) {
			minn[v] = min(minn[v], dist[X[i]] + dist[v] - 2 * dist[lca(X[i], v)]);
			if(v == pCentroid[v])
				break;
			v = pCentroid[v];
		}
	}
	for(int i = 0; i < T; ++i) {
		int v = Y[i];
		while(1) {
			ans = min(ans, dist[Y[i]] + dist[v] - 2 * dist[lca(Y[i], v)] + minn[v]);
			if(v == pCentroid[v])
				break;
			v = pCentroid[v];
		}
	}
	for(int i = 0; i < S; ++i) {
		int v = X[i];
		while(1) {
			minn[v] = inf;
			if(v == pCentroid[v])
				break;
			v = pCentroid[v];
		}
	}
	return ans;
}

Compilation message (stderr)

factories.cpp: In function 'void start(int, int)':
factories.cpp:23:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < g[v].size(); ++i)
                 ~~^~~~~~~~~~~~~

• Subtask 1: 0 / 15
• Subtask 2: 0 / 18
• Subtask 3: 0 / 67