제출 #60667

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
60667		reality	도시들 (IOI15_towns)	C++17	13 / 100	35 ms	1104 KiB

towns

#include "towns.h"
#include "bits/stdc++.h"
using namespace std;
#define fi first
#define se second
#define ll long long
#define dbg(v) cerr<<#v<<" = "<<v<<'\n'
#define vi vector<int>
#define vl vector <ll>
#define pii pair<int,int>
#define mp make_pair
#define db long double
#define pb push_back
#define all(s) s.begin(),s.end()
template < class T > T smin(T &a,T b) {if (a > b) a = b;return a;}
template < class T > T smax(T &a,T b) {if (a < b) a = b;return a;}
 
const int N = 256;
 
int D[N][N];
 
int get(int x,int y) {
	if (D[x][y] != -1)
		return D[x][y];
	return D[x][y] = D[y][x] = getDistance(x,y);
}
 
int hubDistance(int n, int sub) {
	srand(time(0));
	const int root = 0;
	memset(D,-1,sizeof(D));
	int x = 0;
	for (int i = 0;i < n;++i)
		D[i][i] = 0;
	for (int i = 0;i < n;++i)
		if (get(root,i) > get(root,x))
			x = i;
	int y = x;
	for (int i = 0;i < n;++i)
		if (get(x,i) > get(x,y))
			y = i;
	const int Diam = get(x,y);
	int ans = 2e9;
	vi dist(n,0);
	for (int i = 0;i < n;++i) {
		dist[i] = (get(root,i) + get(x,i) - get(root,x)) / 2;
		int dx = get(x,i) - dist[i];
		smin(ans,max(Diam - dx,dx));
	}
	vi was(n,1);
	int a = 0,b = 0;
	for (int i = 0;i < n;++i) {
		int curr = get(x,i) - dist[i];
		if (curr < ans)
			++a,was[i] = 0;
		if (curr > ans)
			++b,was[i] = 0;
	}
	if (max({a,b}) > (n / 2))
		return -ans;
	auto ok = [&](int A,int B) {
		return get(A,B) != dist[A] + dist[B];
	};
	for (int i = 0;i < n;++i)
		if (was[i]) {
			was[i] = 0;
			int cnt = 1;
			for (int j = i + 1;cnt <= (n / 2) && j < n;++j)
				if (was[j] && ok(i,j)) {
					was[j] = 0;
					++cnt;
				}
			if (cnt > (n / 2))
				return -ans;
		}
	return ans;
}

컴파일 시 표준 에러 (stderr) 메시지

towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:29:12: warning: conversion to 'unsigned int' from 'time_t {aka long int}' may alter its value [-Wconversion]
  srand(time(0));
        ~~~~^~~
towns.cpp:28:28: warning: unused parameter 'sub' [-Wunused-parameter]
 int hubDistance(int n, int sub) {
                            ^~~

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