Submission #112624

#	Time	Username	Problem	Language	Result	Execution time	Memory
112624		maruii	공장들 (JOI14_factories)	C++14	0 / 100	90 ms	32760 KiB

factories

#include "factories.h"
#include <bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;
#define ff first
#define ss second
const long long INF = 4e18;

int dfn[500005], dfnn, efn[500005], prt[19][500005];
int dep[500005];
long long D[500005];
vector<pii> edge[500005];

void dfs0(int x, int p) {
	dfn[x] = ++dfnn;
	for (auto i : edge[x]) {
		if (i.ss == p) continue;
		dep[dfnn + 1] = dep[dfn[x]] + 1;
		D[dfnn + 1] = D[dfn[x]] + i.ff;
		prt[0][dfnn + 1] = dfn[x];
		dfs0(i.ss, x);
	}
	efn[dfn[x]] = dfnn;
}

int C[500005], cnt, pv, XY[500005];
long long dp[500005][2], res;

void dfs(int x) {
	dp[x][0] = dp[x][1] = INF;
	if (XY[x] >= 0) dp[x][XY[x]] = 0;
	XY[x] = -1;
	while (pv < cnt && C[pv] <= efn[x]) {
		int i = C[pv++];
		dfs(i);
		dp[x][0] = min(dp[x][0], dp[i][0] + D[i] - D[x]);
		dp[x][1] = min(dp[x][1], dp[i][1] + D[i] - D[x]);
	}
	res = min(res, dp[x][0] + dp[x][1]);
}

int lca(int s, int e) {
	if (dep[s] < dep[e]) swap(s, e);
	for (int i = 18; i >= 0; --i)
		if (((dep[s] - dep[e]) >> i) & 1) s = prt[i][s];
	if (s == e) return s;
	for (int i = 18; i >= 0; --i)
		if (prt[i][s] != prt[i][e]) s = prt[i][s], e = prt[i][e];
	return prt[0][s];
}

long long Query(int S, int X[], int T, int Y[]) {
	cnt = 0;
	for (int i = 0; i < S; ++i) C[cnt] = dfn[X[i]], XY[dfn[X[i]]] = 0;
	for (int i = 0; i < T; ++i) C[cnt] = dfn[Y[i]], XY[dfn[Y[i]]] = 1;
	sort(C, C + cnt);
	for (int i = cnt-1; i; --i) C[cnt++] = lca(C[i - 1], C[i]);
	sort(C, C + cnt);
	cnt = unique(C, C + cnt) - C;
	res = INF, pv = 0;
	dfs(1);
	return res;
}

void Init(int N, int A[], int B[], int D[]) {
	for (int i = 0; i < N - 1; ++i) {
		edge[A[i]].emplace_back(D[i], B[i]);
		edge[B[i]].emplace_back(D[i], A[i]);
	}
	dfs0(0, 0);
	memset(XY, -1, sizeof(XY));
	for (int i = 1; i < 19; ++i) for (int j = 1; j <= N; ++j) prt[i][j] = prt[i - 1][prt[i - 1][j]];
}

Compilation message (stderr)

In function 'long long int Query(int, int*, int, int*)':
cc1plus: warning: iteration 2147483648 invokes undefined behavior [-Waggressive-loop-optimizations]
factories.cpp:57:22: note: within this loop
  for (int i = cnt-1; i; --i) C[cnt++] = lca(C[i - 1], C[i]);
                      ^
factories.cpp:57:44: warning: array subscript is below array bounds [-Warray-bounds]
  for (int i = cnt-1; i; --i) C[cnt++] = lca(C[i - 1], C[i]);
                                         ~~~^~~~~~~~~~~~~~~~
factories.cpp:57:44: warning: array subscript is below array bounds [-Warray-bounds]

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