Submission #764756

#	Time	Username	Problem	Language	Result	Execution time	Memory
764756		SanguineChameleon	Towns (IOI15_towns)	C++17	35 / 100	12 ms	404 KiB

towns

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

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

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, int> cnt;
	for (int i = 0; i < N; i++) {
		int mid = (dist(X, i) + dist(Y, i) - dist(X, Y)) / 2;
		int left = dist(X, i) - mid;
		int right = dist(Y, i) - mid;
		cnt[left]++;
		R = min(R, max(left, right));
	}
	int pref = 0;
	int suf = N;
	for (auto p: cnt) {
		suf -= p.second;
		if (max(p.first, dist(X, Y) - p.first) == R && pref <= N / 2 && suf <= N / 2) {
			if (p.second <= N / 2) {
				return R;
			}
		}
		pref += p.second;
	}
	return -R;
}

Compilation message (stderr)

towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:17:28: warning: unused parameter 'sub' [-Wunused-parameter]
   17 | int hubDistance(int N, int sub) {
      |                        ~~~~^~~

• Subtask 1: 13 / 13
• Subtask 2: 12 / 12
• Subtask 3: 0 / 13
• Subtask 4: 10 / 10
• Subtask 5: 0 / 13
• Subtask 6: 0 / 39