Submission #790751

#	Time	Username	Problem	Language	Result	Execution time	Memory
790751		peteza	Simurgh (IOI17_simurgh)	C++14	51 / 100	87 ms	7500 KiB

simurgh

#include "simurgh.h"
#include <iostream>
#include <algorithm>
#include <cstring>
#include <cassert>
using namespace std;
using pii = pair<int, int>;

int ct, ign;
bool vis[505];
vector<pii> adj[505];
vector<int> times[505];
bool checked[50505];
int inside[50505];

void dfs(int x, vector<int> &to) {
	for(pii e:adj[x]) {
		if(e.first == ign) {
			times[ct].push_back(e.second);
			continue;
		}
		if(vis[e.first]) continue;
		vis[e.first] = 1; 
		to.push_back(e.second);
		dfs(e.first, to);
	}
}

std::vector<int> find_roads(int n, std::vector<int> u, std::vector<int> v) {
	std::vector<int> r;
	int m = u.size();
	for(int i=0;i<m;i++) adj[u[i]].emplace_back(v[i], i), adj[v[i]].emplace_back(u[i], i);
	for(int i=0;i<n;i++) {
		for(int j=0;j<n;j++) times[j].clear();
		//with this node as the main node, generate a spanning tree ignoring this node
		ign = i;
		std::vector<int> toask;
		memset(vis, 0, sizeof vis); vis[i] = 1;
		for(int j=0;j<n;j++) {
			ct = j;
			if(!vis[j]) vis[j] = 1, dfs(j, toask);
		}
		int cq = 0;
		for(int ctime = 0;ctime<n;ctime++) {
			if(times[ctime].empty()) continue;
			for(int ktime=0;ktime<n;ktime++) {
				if(ktime == ctime) continue;
				if(times[ktime].size()) toask.push_back(times[ktime][0]);
			}
			std::vector<int> inans;
			int mx = -1;
			bool once = 0;
			for(int e:times[ctime]) {
				if(checked[e]) {
					if(!inside[e] || once) continue;
					once = 1;
				}
				toask.push_back(e);
				checked[e] = 1;
				assert(toask.size() == n-1 && cq++ <= 30000);
				int res = count_common_roads(toask);
				if(res >= mx) {
					if(res > mx) inans.clear();
					mx = res;
					inans.push_back(e);
				}
				toask.pop_back();
			}
			for(int ktime=0;ktime<n;ktime++) {
				if(ktime == ctime) continue;
				if(times[ktime].size()) toask.pop_back();
			}
			for(int e:inans) inside[e] = 1, r.push_back(e);
		}
	}
	sort(r.begin(), r.end());
	r.resize(unique(r.begin(), r.end())-r.begin());
	return r;
}

/*
4 6
0 1
0 2
0 3
1 2
1 3
2 3
0 1 5
*/

Compilation message (stderr)

In file included from /usr/include/c++/10/cassert:44,
                 from simurgh.cpp:5:
simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:60:25: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   60 |     assert(toask.size() == n-1 && cq++ <= 30000);
      |            ~~~~~~~~~~~~~^~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 17 / 17
• Subtask 3: 21 / 21
• Subtask 4: 0 / 19
• Subtask 5: 0 / 30