Submission #103806

#	Time	Username	Problem	Language	Result	Execution time	Memory
103806		igba	Factories (JOI14_factories)	C++17	15 / 100	8085 ms	95644 KiB

factories

#include <bits/stdc++.h>
#include "factories.h"
 
using namespace std;
#define mkp make_pair
const int MAXN = 5 * 100100, MAXLN = 20;
const long long LINF = 0x3f3f3f3f3f3f3f3f;
int n, sz[MAXN], cdp[MAXN], memo[MAXN][MAXLN], lvl[MAXN];
long long distrt[MAXN], aux[MAXN];
bool rmd[MAXN];
vector<pair<int, int>> g[MAXN];

void szdfs(int v, int p = -1)
{
	sz[v] = 1;
	for(const auto&[w, u] : g[v])
		if(u != p && !rmd[u])
			szdfs(u, v), sz[v] += sz[u];
}

int getCentroid(int v, int p = -1, int rt = -1)
{
	if(rt == -1)
		rt = v;
	for(const auto&[w, u] : g[v])
		if(u != p && !rmd[u] && sz[u] > sz[rt] / 2)
			return getCentroid(u, v, rt);
	return v;
}

void cd(int v, int cp = -1)
{
	szdfs(v);
	int c = getCentroid(v);
	cdp[c] = cp, rmd[c] = true;
	for(const auto&[w, u] : g[c])
		if(!rmd[u])
			cd(u, c);
}

void lcadfs(int v, int p = -1)
{
	for(const auto&[w, u] : g[v])
		if(u != p)
			lvl[u] = lvl[v] + 1, memo[u][0] = v, distrt[u] = distrt[v] + w, lcadfs(u, v);
}

int dp(int v, int i)
{
	if(memo[v][i] != -1)
		return memo[v][i];
	return memo[v][i] = dp(dp(v, i - 1), i - 1);
}

int lca(int u, int v)
{
	if(lvl[u] < lvl[v])
		swap(u, v);
	for(int i = MAXLN - 1; i >= 0; --i)
		if(lvl[u] - (1 << i) >= lvl[v])
			u = dp(u, i);
	if(u == v)
		return u;
	for(int i = MAXLN - 1; i >= 0; --i)
		if(lvl[u] - (1 << i) >= 0 && dp(u, i) != dp(v, i))
			u = dp(u, i), v = dp(v, i);
	return dp(u, 0);
}

long long getdist(int u, int v)
{
	return distrt[u] + distrt[v] - 2 * distrt[lca(u, v)];
}

void Init(int N, int A[], int B[], int D[])
{
	memset(memo, -1, sizeof memo);
	n = N;
	for(int i = 0; i < n - 1; ++i)
		g[A[i]].push_back(mkp(D[i], B[i])), g[B[i]].push_back(mkp(D[i], A[i]));
	cd(0), lcadfs(0);
}

long long Query(int S, int X[], int T, int Y[])
{
	long long ans = LINF;
	for(int i = 0; i < n; ++i)
		aux[i] = LINF;
	for(int i = 0, cur; i < S; ++i)
	{
		cur = X[i];
		while(cur != -1)
		{
			aux[cur] = min(aux[cur], getdist(cur, X[i]));
			cur = cdp[cur];
		}
	}
	for(int i = 0, cur; i < T; ++i)
	{
		cur = Y[i];
		while(cur != -1)
		{
			ans = min(ans, aux[cur] + getdist(Y[i], cur));
			cur = cdp[cur];
		}
	}
	return ans;
}

Compilation message (stderr)

factories.cpp: In function 'void szdfs(int, int)':
factories.cpp:16:22: warning: unused variable 'w' [-Wunused-variable]
  for(const auto&[w, u] : g[v])
                      ^
factories.cpp: In function 'int getCentroid(int, int, int)':
factories.cpp:25:22: warning: unused variable 'w' [-Wunused-variable]
  for(const auto&[w, u] : g[v])
                      ^
factories.cpp: In function 'void cd(int, int)':
factories.cpp:36:22: warning: unused variable 'w' [-Wunused-variable]
  for(const auto&[w, u] : g[c])
                      ^

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