Submission #963864

#	Time	Username	Problem	Language	Result	Execution time	Memory
963864		guechotjrhh	City Mapping (NOI18_citymapping)	C++14	25 / 100	4 ms	856 KiB

citymapping

#include "citymapping.h"
#include<vector>
#include<algorithm>
#include<random>
using namespace std;
#define ll long long
#define pi pair<ll,ll>
#define x first
#define y second

random_device rd;
mt19937 g(rd());

int* a, * b, * w;
int t = 0;
void rec(vector<int>& v) {
	int n = v.size();
	if (n == 1) return;
	shuffle(v.begin(), v.end(), g);
	int u1 = v[0], u2 = v[1];
	vector<ll> d1(n, 0), d2(n, 0);
	vector<int> v1, v2;
	int t1 = 1, t2 = 0;
	for (int i = 0; i < n; i++) {
		if (v[i] != u1) d1[i] = get_distance(v[i], u1);
		if (v[i] != u2) d2[i] = get_distance(v[i], u2);

		if (d1[i] < d2[i]) {
			v1.push_back(v[i]);
			if (d2[i] < d2[t2]) t2 = i;
		}
		else {
			v2.push_back(v[i]);
			if (d1[i] < d1[t1]) t1 = i;
		}
	}
	a[t] = v[t1]; b[t] = v[t2]; w[t] = d1[t1] - d1[t2]; t++;
	rec(v1);
	rec(v2);
}
void find_roads(int N, int Q, int A[], int B[], int W[]) {
	a = A; b = B; w = W;
	/*ll u = 0, mi = 1;
	for (int i = 2; i <= N; i++) {
		ll x = get_distance(1, i);
		if (x > u) {
			u = x;
			mi = i;
		}
	}
	vector<pi> vec;
	for (int i = 1; i <= N; i++) {
		if (i != mi) vec.push_back({ get_distance(mi,i),i });
	}
	sort(vec.begin(), vec.end());
	A[0] = mi; B[0] = vec[0].y; W[0] = vec[0].x;
	for (int i = 1; i < N-1; i++) {
		A[i] = vec[i].y; B[i] = vec[i - 1].y; W[i] = vec[i].x - vec[i - 1].x;
	}*/

	vector<int> v(N); for (int i = 1; i <= N; i++) v[i - 1] = i;
	rec(v);

	return;
}
/*
5 500000 1
1 4 8
4 2 1
4 3 7
3 5 3
*/

• Subtask 1: 9 / 9
• Subtask 2: 16 / 16
• Subtask 3: 0 / 13
• Subtask 4: 0 / 19
• Subtask 5: 0 / 43