Submission #321512

#	Time	Username	Problem	Language	Result	Execution time	Memory
321512		NachoLibre	Stations (IOI20_stations)	C++14	100 / 100	1124 ms	1280 KiB

stations

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

const int N = 1003;
vector<int> v[N], dr;
int tn;

void sgd(int dg, int op, int dt) {
	if(dt & 1 ^ 1) dr[dg] = tn, ++tn;
	for(int i = 0; i < v[dg].size(); ++i) {
		if(v[dg][i] != op) {
			sgd(v[dg][i], dg, dt + 1);
		}
	}
	if(dt & 1) dr[dg] = tn, ++tn;
}

vector<int> label(int n, int k, vector<int> x, vector<int> y) {
	for(int i = 0; i < n; ++i) v[i].clear();
	for(int i = 0; i < n - 1; ++i) {
		v[x[i]].push_back(y[i]);
		v[y[i]].push_back(x[i]);
	}
	dr.clear();
	for(int i = 0; i < n; ++i) dr.push_back(0);
	tn = 0;
	sgd(0, -1, 0);
	return dr;
}

int find_next_station(int a, int b, vector<int> v) {
	int n = v.size();
	if(a == 0) {
		sort(v.begin(), v.end());
		for(int i = 0; i < n; ++i) {
			if(b <= v[i]) return v[i];
		}
		assert(0);
	} else if(v[0] > a) {
		sort(v.begin(), v.end());
		if(b < a) return v[n - 1];
		for(int i = 0; i < n - 1; ++i) {
			if(b <= v[i]) return v[i];
		}
		return v[n - 1];
	} else {
		if(n == 1) return v[0];
		sort(v.begin(), v.end());
		v.push_back(v[0]);
		for(int i = 0; i < n; ++i) v[i] = v[i + 1];
		v.pop_back();
		if(b < v[0]) return v[n - 1];
		if(b > a) return v[n - 1];
		for(int i = 1; i < n - 1; ++i) {
			if(b < v[i]) return v[i - 1];
		}
		return v[n - 2];
	}
}

////////////
//
// vector<int> ve[N], xv, yv;
//
// void add(int a, int b) {
// 	xv.push_back(a);
// 	yv.push_back(b);
// 	ve[a].push_back(b);
// 	ve[b].push_back(a);
// }
//
// vector<int> drv(vector<int> v) {
// 	for(int i = 0; i < v.size(); ++i) {
// 		v[i] = dr[v[i]];
// 	}
// 	return v;
// }
//
// int dwb, dwm;
// void sgd(int dg, int op) {
// 	cout << dwb << " > " << dg << " = " << find_next_station(dr[dwb], dr[dg], drv(ve[dwb])) << " --> " << dr[dwm] << endl;
// 	for(int i = 0; i < ve[dg].size(); ++i) {
// 		if(ve[dg][i] != op) {
// 			sgd(ve[dg][i], dg);
// 		}
// 	}
// }
//
// int main() {
// 	ios::sync_with_stdio(0);
// 	cin.tie(0);
// 	int n = 5;
// 	add(0, 1);
// 	add(0, 2);
// 	add(1, 3);
// 	add(1, 4);
// 	dr = label(n, n, xv, yv);
// 	for(dwb = 0; dwb < n; ++dwb) {
// 		for(int i = 0; i < ve[dwb].size(); ++i) {
// 			dwm = ve[dwb][i];
// 			sgd(dwm, dwb);
// 		}
// 	}
// 	return 0;
// 	dr = label(5, 4, {0, 1, 1, 2}, {1, 2, 3, 4});
// 	cout << find_next_station(dr[2], dr[0], {dr[1], dr[4]}) << " --> " << dr[1] << endl;
// 	cout << find_next_station(dr[1], dr[3], {dr[3], dr[2], dr[0]}) << " --> " << dr[3] << endl;
// 	cout << find_next_station(dr[4], dr[3], {dr[2]}) << " --> " << dr[2] << endl;
// 	return 0;
// }

Compilation message (stderr)

stations.cpp: In function 'void sgd(int, int, int)':
stations.cpp:9:8: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
    9 |  if(dt & 1 ^ 1) dr[dg] = tn, ++tn;
      |     ~~~^~~
stations.cpp:10:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   10 |  for(int i = 0; i < v[dg].size(); ++i) {
      |                 ~~^~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 8 / 8
• Subtask 3: 16 / 16
• Subtask 4: 10 / 10
• Subtask 5: 61 / 61