oj.uz

Submission #258065

# Submission time Handle Problem Language Result Execution time Memory
258065 2020-08-05T09:48:01 Z atoiz Sky Walking (IOI19_walk) C++14
25 / 100
 4000 ms 81348 KB 
#include "walk.h"
#include <iostream>
#include <vector>
#include <algorithm>
#include <cstdio>
#include <cmath>
#include <tuple>
#include <cassert>
#include <numeric>
 
using namespace std;
using ll = long long;
 
const int MAXY = 1000100100;
const ll INFLL = 1e16;
int N, M, T;
vector<int> X, H, L, R, Y;
vector<int> valY;
 
int dist(int i, int j) { return abs(X[i] - X[j]); }
// int pos(int y) { return (int) (upper_bound(valY.begin(), valY.end(), y) - valY.begin() - 1); } // first <=
 
struct SegmentTree {
	vector<ll> lazy, arr;
	vector<int> cnt;
	SegmentTree(): lazy((T + 2) * 4, INFLL), arr((T + 2) * 4, INFLL), cnt((T + 2) * 4, 0) {}
 
	void push(int rt, int lo, int hi) {
		if (lazy[rt] != INFLL && cnt[rt]) {
			if (lo == hi) arr[lo] = min(arr[lo], lazy[rt]);
			else {
				int lc = rt << 1, rc = rt << 1 | 1, md = (lo + hi) >> 1;
				lazy[lc] = min(lazy[lc], lazy[rt]), lazy[rc] = min(lazy[rc], lazy[rt]);
			}
		}
		lazy[rt] = INFLL;
	}
 
	void insert(int y, ll c) {
		int rt = 1, lo = 0, hi = T - 1;
		while (true) {
			push(rt, lo, hi);
			++cnt[rt];
			if (lo == hi) {
				assert(valY[lo] == y);
				arr[lo] = min(arr[lo], c);
				break;
			}
			int md = (lo + hi) >> 1;
			(y <= valY[md]) ? (rt = rt << 1, hi = md) : (rt = rt << 1 | 1, lo = md + 1);
		}
	}
 
	void remove(int y) {
		int rt = 1, lo = 0, hi = T - 1;
		while (true) {
			push(rt, lo, hi);
			--cnt[rt];
			if (lo == hi) {
				if (cnt[rt] == 0) arr[lo] = INFLL;
				break;
			}
			int md = (lo + hi) >> 1;
			(y <= valY[md]) ? (rt = rt << 1, hi = md) : (rt = rt << 1 | 1, lo = md + 1);
		}
	}
 
	void minimize(int l, int r, ll c, int rt, int lo, int hi) {
		if (valY[hi] < l || r < valY[lo] || !cnt[rt]) return;
		push(rt, lo, hi);
		if (l <= valY[lo] && valY[hi] <= r) return lazy[rt] = min(lazy[rt], c), void(0);
		int lc = rt << 1, rc = rt << 1 | 1, md = (lo + hi) >> 1;
		minimize(l, r, c, lc, lo, md), minimize(l, r, c, rc, md + 1, hi);
	}
	void minimize(int l, int r, ll c) { minimize(l, r, c, 1, 0, T - 1); }
 
	ll get(int l, int r, bool minY, int rt, int lo, int hi) {
		if (valY[hi] < l || r < valY[lo] || !cnt[rt]) return INFLL;
		push(rt, lo, hi);
		if (lo == hi) return arr[lo];
		int lc = rt << 1, rc = rt << 1 | 1, md = (lo + hi) >> 1;
 
		ll ans = INFLL;
		if (minY) {
			ans = get(l, r, minY, lc, lo, md);
			if (ans == INFLL) ans = get(l, r, minY, rc, md + 1, hi);
		} else {
			ans = get(l, r, minY, rc, md + 1, hi);
			if (ans == INFLL) ans = get(l, r, minY, lc, lo, md);
		}
		return ans;
	}
	ll get(int l, int r, bool minY) { return get(l, r, minY, 1, 0, T - 1); }
};
 
vector<vector<pair<int, ll>>> solve(int start) {
	// cout << "solve " << start << endl;
	vector<vector<pair<int, ll>>> ans(M);
 
	vector<vector<int>> walksAdd(N), walksRem(N);
	vector<int> walkL(M, -1), walkR(M, -1);
	vector<int> walkIDs(M);
	iota(walkIDs.begin(), walkIDs.end(), 0);
	sort(walkIDs.begin(), walkIDs.end(), [&](int i, int j) { return Y[i] < Y[j]; });
	vector<int> lCols, rCols;
	for (int x = 0; x <= start; lCols.push_back(x++)) while (!lCols.empty() && H[lCols.back()] <= H[x]) lCols.pop_back();
	for (int x = N - 1; x >= start; rCols.push_back(x--)) while (!rCols.empty() && H[rCols.back()] <= H[x]) rCols.pop_back();
	for (int w : walkIDs) {
		if (L[w] <= start && start <= R[w] && Y[w] <= H[start]) { 
			walksAdd[walkL[w] = walkR[w] = start].push_back(w);
			walksRem[L[w]].push_back(w), walksRem[R[w]].push_back(w);
			continue; 
		}
 
		while (!lCols.empty() && H[lCols.back()] < Y[w]) lCols.pop_back();
		while (!rCols.empty() && H[rCols.back()] < Y[w]) rCols.pop_back();
		if (!rCols.empty() && rCols.back() <= L[w]) walksAdd[L[w]].push_back(w), walksRem[R[w]].push_back(w);
		else if (!lCols.empty() && lCols.back() >= R[w]) walksAdd[R[w]].push_back(w), walksRem[L[w]].push_back(w);
		else {
			if (!lCols.empty() && L[w] <= lCols.back()) walksAdd[walkL[w] = lCols.back()].push_back(w), walksRem[L[w]].push_back(w);
			if (!rCols.empty() && R[w] >= rCols.back()) walksAdd[walkR[w] = rCols.back()].push_back(w), walksRem[R[w]].push_back(w);
		}
	}
 
	// for (int x = 0; x < N; ++x) {
	// 	cout << x << ":\n";
	// 	for (auto w : walksRem[x]) cout << L[w] << ' ' << R[w] << ' ' << Y[w] << endl;
	// }
 
	vector<vector<SegmentTree>> st(2, vector<SegmentTree>(2, SegmentTree()));
	for (int w : walksAdd[start]) {
		if (L[w] < start) st[0][0].insert(Y[w], 0), st[0][1].insert(Y[w], Y[w]);
		if (R[w] > start) st[1][0].insert(Y[w], 0), st[1][1].insert(Y[w], Y[w]);
		ans[w].emplace_back(start, 0);
	}
 
	vector<vector<pair<int, ll>>> updates(N);
	int leftBorder = start, rightBorder = start;
	while (leftBorder > 0 || rightBorder < N - 1) {
		ll leftBest = st[0][0].get(0, MAXY, false), rightBest = st[1][0].get(0, MAXY, false);
		bool k = leftBest > rightBest;
		if (leftBorder == 0) k = 1;
		if (rightBorder == N - 1) k = 0;
 
		int col = (k == 0 ? --leftBorder : ++rightBorder);
 
		for (int w : walksAdd[col]) {
			ll curCost = min(st[k][0].get(0, Y[w], false), st[k][1].get(Y[w], H[col], true) - Y[w]);
			st[k][0].insert(Y[w], curCost), st[k][1].insert(Y[w], curCost + Y[w]);
			// cout << "pre dist " << col << ' ' << Y[w] << ": " << curCost << endl;
		}
 
		// cout << "S" << endl;
		for (auto upd : updates[col]) {
			// cout << "." << endl;
			int y = upd.first;
			ll c = upd.second;
			st[k][0].minimize(y, MAXY, c), st[k][1].minimize(0, y, c + y);
		}
		// cout << "T" << endl;
		for (int w : walksAdd[col]) {
			ll curCost = min(st[k][0].get(Y[w], Y[w], false), st[k][1].get(Y[w], Y[w], false) - Y[w]);
			// cout << "dist " << col << ' ' << Y[w] << ": " << curCost << endl;
			ans[w].emplace_back(col, curCost);
 
			if (~walkL[w] && ~walkR[w] && walkL[w] <= start && start <= walkR[w]) {
				if (col == walkL[w]) updates[walkR[w]].emplace_back(Y[w], curCost + X[start] - X[col]);
				if (col == walkR[w]) updates[walkL[w]].emplace_back(Y[w], curCost + X[col] - X[start]);
			}
		}
 
		for (int w : walksRem[col]) st[k][0].remove(Y[w]), st[k][1].remove(Y[w]);
	}
 
	return ans;
}
 
ll min_distance(vector<int> x, vector<int> h, vector<int> l, vector<int> r, vector<int> y, int s, int t) {
	N = (int) x.size(), M = (int) y.size();
	X = x, H = h, L = l, R = r, Y = y;
	valY = Y;
	sort(valY.begin(), valY.end()), valY.erase(unique(valY.begin(), valY.end()), valY.end());
	T = (int) valY.size();
 
	vector<vector<pair<int, ll>>> ansS = solve(s);
	vector<vector<pair<int, ll>>> ansT = solve(t);
	ll ans = INFLL;
	for (int j = 0; j < M; ++j) {
		for (auto p : ansS[j]) for (auto q : ansT[j]) {
			ll cur = 0;
			cur += (ll) Y[j] * 2;
			cur += (ll) dist(p.first, q.first) + dist(p.first, s) + dist(q.first, t);
			cur += (p.second + q.second) * 2;
			// if (cur == 27) cout << L[j] << ' ' << R[j] << ' ' << Y[j] << " - " << p.first << ' ' << q.first << endl;
			ans = min(ans, cur);
		}
	}
 
	if (ans == INFLL) ans = -1;
	return ans;
}

Compilation message

walk.cpp: In member function 'void SegmentTree::push(int, int, int)':
walk.cpp:32:41: warning: unused variable 'md' [-Wunused-variable]
     int lc = rt << 1, rc = rt << 1 | 1, md = (lo + hi) >> 1;
                                         ^~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 256 KB Output is correct
2 Correct 0 ms 256 KB Output is correct
3 Correct 1 ms 256 KB Output is correct
4 Correct 0 ms 256 KB Output is correct
5 Correct 1 ms 384 KB Output is correct
6 Correct 0 ms 384 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 0 ms 256 KB Output is correct
10 Correct 1 ms 384 KB Output is correct
11 Correct 1 ms 384 KB Output is correct
12 Correct 1 ms 384 KB Output is correct
13 Correct 1 ms 384 KB Output is correct
14 Correct 0 ms 384 KB Output is correct
15 Correct 1 ms 384 KB Output is correct
16 Correct 1 ms 384 KB Output is correct
17 Correct 1 ms 384 KB Output is correct

Subtask #2
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 256 KB Output is correct
2 Correct 1 ms 256 KB Output is correct
3 Correct 658 ms 70380 KB Output is correct
4 Incorrect 883 ms 80492 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 69 ms 9968 KB Output is correct
2 Correct 619 ms 69272 KB Output is correct
3 Correct 649 ms 70672 KB Output is correct
4 Correct 845 ms 79172 KB Output is correct
5 Correct 763 ms 77768 KB Output is correct
6 Correct 741 ms 79072 KB Output is correct
7 Correct 383 ms 44728 KB Output is correct
8 Correct 787 ms 81348 KB Output is correct
9 Correct 731 ms 80252 KB Output is correct
10 Correct 411 ms 51492 KB Output is correct
11 Correct 21 ms 5120 KB Output is correct

Subtask #4
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 69 ms 9968 KB Output is correct
2 Correct 619 ms 69272 KB Output is correct
3 Correct 649 ms 70672 KB Output is correct
4 Correct 845 ms 79172 KB Output is correct
5 Correct 763 ms 77768 KB Output is correct
6 Correct 741 ms 79072 KB Output is correct
7 Correct 383 ms 44728 KB Output is correct
8 Correct 787 ms 81348 KB Output is correct
9 Correct 731 ms 80252 KB Output is correct
10 Correct 411 ms 51492 KB Output is correct
11 Correct 21 ms 5120 KB Output is correct
12 Correct 736 ms 70580 KB Output is correct
13 Execution timed out 4064 ms 73604 KB Time limit exceeded
14 Halted 0 ms 0 KB -

Subtask #5
0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 256 KB Output is correct
2 Correct 0 ms 256 KB Output is correct
3 Correct 1 ms 256 KB Output is correct
4 Correct 0 ms 256 KB Output is correct
5 Correct 1 ms 384 KB Output is correct
6 Correct 0 ms 384 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 0 ms 256 KB Output is correct
10 Correct 1 ms 384 KB Output is correct
11 Correct 1 ms 384 KB Output is correct
12 Correct 1 ms 384 KB Output is correct
13 Correct 1 ms 384 KB Output is correct
14 Correct 0 ms 384 KB Output is correct
15 Correct 1 ms 384 KB Output is correct
16 Correct 1 ms 384 KB Output is correct
17 Correct 1 ms 384 KB Output is correct
18 Correct 0 ms 256 KB Output is correct
19 Correct 1 ms 256 KB Output is correct
20 Correct 658 ms 70380 KB Output is correct
21 Incorrect 883 ms 80492 KB Output isn't correct
22 Halted 0 ms 0 KB -