Submission #283789

#	Time	Username	Problem	Language	Result	Execution time	Memory
283789		emanIaicepsa	Simurgh (IOI17_simurgh)	C++14	30 / 100	64 ms	5992 KiB

simurgh

#include "simurgh.h"
#include<bits/stdc++.h>
#define pb emplace_back
#define vi vector<int>
#define pii pair<int,int>
#define fi first
#define se second
#define all(n) (n).begin(),(n).end()
using namespace std;

vi ans, pos, pos2, U, V;

int pa[505], N, M;
void init(){
	for(int i=0;i<N;i++) pa[i] = i;
}
int fp(int x){
	if(pa[x] == x) return x;
	return pa[x] = fp(pa[x]);
}
void uni(int x,int y){
	x = fp(x), y = fp(y);
	assert(x != y);
	pa[x] = y;
}

bool dead[25005];
void search_next(){
	init();
	int cnt = N;
	pos.clear();
	for(int i=0;i<M;i++) if(!dead[i]) pos.pb(i);
	random_shuffle(all(pos));
	vi cur;
	for(auto &i:ans){
		uni(U[i], V[i]);
		cur.pb(i);
		cnt--;
	}
	vector<pii> tried;
	for(auto &i:pos){
		if(cnt == 2){
			if(fp(U[i]) != fp(V[i])){
				cur.pb(i);
				assert(cur.size() == N-1);
				int common = count_common_roads(cur); 
				/* cout<<common<<" "<<i<<'\n'; */
				tried.pb(common,i);
				cur.pop_back();
			}
			else pos2.pb(i);
		}
		else{
			if(fp(U[i]) != fp(V[i])){
				cur.pb(i);
				uni(U[i], V[i]);
				cnt--;
			}
			pos2.pb(i);
		}
	}
	pair<int,int> mx = *max_element(all(tried));
	int presiz = ans.size();
	for(auto &x : tried){
		bool notmore = 0;
		if(x.fi == mx.fi){
			ans.pb(x.se), dead[x.se] = 1;
		}
		else if(x.fi == presiz && !notmore){
			notmore = 1;
			for(auto &i:cur) dead[x.se] = 1;
		}
	}
	/* for(auto i:pos) cout<<i<<" "; cout<<'\n'; */
}
// count_common_roads(vi v);

std::vector<int> find_roads(int n, std::vector<int> u, std::vector<int> v) {
	srand(time(0));
	M = u.size(), N = n;
	U = u, V = v;
	for(int i=0;i<M;i++) pos.pb(i);
	while(ans.size() < N - 1) search_next();
	/* for(auto i:ans) cout<<i<<" "; cout<<'\n'; */
	return ans;
}

Compilation message (stderr)

In file included from /usr/include/c++/9/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/9/bits/stdc++.h:33,
                 from simurgh.cpp:2:
simurgh.cpp: In function 'void search_next()':
simurgh.cpp:45:23: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   45 |     assert(cur.size() == N-1);
      |            ~~~~~~~~~~~^~~~~~
simurgh.cpp:71:14: warning: unused variable 'i' [-Wunused-variable]
   71 |    for(auto &i:cur) dead[x.se] = 1;
      |              ^
simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:83:19: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   83 |  while(ans.size() < N - 1) search_next();
      |        ~~~~~~~~~~~^~~~~~~

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