oj.uz

Submission #765031

# Submission time Handle Problem Language Result Execution time Memory
765031 2023-06-24T07:46:12 Z SanguineChameleon Towns (IOI15_towns) C++17
100 / 100
 20 ms 904 KB 
#include "towns.h"
#include <bits/stdc++.h>
using namespace std;

const int maxN = 1e2 + 20;
int memo[maxN][maxN];
int depth[maxN];

int dist(int u, int v) {
	if (memo[u][v] != -1) {
		return memo[u][v];
	}
	else {
		return memo[u][v] = memo[v][u] = getDistance(u, v);
	}
}

bool equal(int u, int v) {
	if (u == v) {
		return true;
	}
	else if (u == -1 || v == -1) {
		return false;
	}
	else {
		return depth[u] + depth[v] != dist(u, v);
	}
}

bool check(vector<int> comp) {
	vector<int> bucket;
	vector<int> list;
	for (auto u: comp) {
		if (list.empty() || !equal(list.back(), u)) {
			list.push_back(u);
			if (!bucket.empty()) {
				list.push_back(bucket.back());
				bucket.pop_back();
			}
		}
		else {
			bucket.push_back(u);
		}
	}
	int u = list.back();
	while (!list.empty()) {
		int v = list.back();
		list.pop_back();
		if (equal(u, v)) {
			if (!list.empty()) {
				list.pop_back();
			}
			else {
				bucket.push_back(v);
			}
		}
		else {
			if (bucket.empty()) {
				return true;
			}
			bucket.pop_back();
		}
	}
	return bucket.empty();
}

int hubDistance(int N, int sub) {
	for (int i = 0; i < N; i++) {
		for (int j = 0; j < N; j++) {
			memo[i][j] = (i == j ? 0 : -1);
		}
	}
	int X = 0;
	for (int i = 0; i < N; i++) {
		if (dist(0, i) > dist(0, X)) {
			X = i;
		}
	}
	int Y = 0;
	for (int i = 0; i < N; i++) {
		if (dist(X, i) > dist(X, Y)) {
			Y = i;
		}
	}
	int R = dist(X, Y);
	map<int, vector<int>> comps;
	for (int i = 0; i < N; i++) {
		depth[i] = (dist(X, i) + dist(0, i) - dist(X, 0)) / 2;
		int left = dist(X, i) - depth[i];
		int right = dist(X, Y) - left;
		comps[left].push_back(i);
		R = min(R, max(left, right));
	}
	int pref = 0;
	int suf = N;
	for (auto p: comps) {
		suf -= (int)p.second.size();
		if (max(p.first, dist(X, Y) - p.first) == R && pref <= N / 2 && suf <= N / 2) {
			if ((int)p.second.size() <= N / 2) {
				return R;
			}
			else {
				p.second.resize(N, -1);
				if (check(p.second)) {
					return R;
				}
			}
		}
		pref += (int)p.second.size();
	}
	return -R;
}

Compilation message

towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:67:28: warning: unused parameter 'sub' [-Wunused-parameter]
   67 | int hubDistance(int N, int sub) {
      |                        ~~~~^~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 340 KB Output is correct
2 Correct 11 ms 408 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 16 ms 404 KB Output is correct
5 Correct 12 ms 340 KB Output is correct

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 404 KB Output is correct
2 Correct 11 ms 412 KB Output is correct
3 Correct 12 ms 340 KB Output is correct
4 Correct 13 ms 400 KB Output is correct

Subtask #3
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 340 KB Output is correct
2 Correct 16 ms 404 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 13 ms 404 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 400 KB Output is correct

Subtask #5
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 340 KB Output is correct
2 Correct 13 ms 436 KB Output is correct
3 Correct 13 ms 412 KB Output is correct

Subtask #6
39.0 / 39.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 340 KB Output is correct
2 Correct 13 ms 904 KB Output is correct
3 Correct 20 ms 896 KB Output is correct