Submission #300698

#	Time	Username	Problem	Language	Result	Execution time	Memory
300698		AmineWeslati	Connecting Supertrees (IOI20_supertrees)	C++14	46 / 100	276 ms	30200 KiB

supertrees

//Never stop trying
#include "supertrees.h"
#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#define boost ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)

typedef string str;
typedef long long ll;
//#define int ll
typedef double db;
typedef long double ld;
typedef pair<int, int> pi;
#define fi first
#define se second
typedef vector<int> vi;
typedef vector<pi> vpi;
typedef vector<str> vs;
typedef vector<ld> vd;
#define pb push_back
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define endl "\n"

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)

const int MOD = 1e9 + 7; //998244353
const ll INF = 1e18;
const int MX = 1001;
const int nx[4] = {0, 0, 1, -1}, ny[4] = {1, -1, 0, 0}; //right left down up

template<class T> using V = vector<T>;
template<class T> bool ckmin(T& a, const T& b) { return a > b ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }

ll cdiv(ll a, ll b) { return a / b + ((a ^ b) > 0 && a % b); } // divide a by b rounded up
constexpr int log2(int x) { return 31 - __builtin_clz(x); } // floor(log2(x))

#define dbg(x) cerr << " - " << #x << " : " << x << endl;
#define dbgs(x,y) cerr << " - " << #x << " : " << x << " / " << #y << " : " << y << endl;
#define dbgv(v) cerr << " - " << #v << " : " << endl << "[ "; for(auto it : v) cerr << it << ' '; cerr << ']' << endl;

void IO() {
#ifndef ONLINE_JUDGE
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
#endif
}



int N;
int p[MX][MX];
vi adj[MX];
bool vis[MX]; set<int> s;

vi adj2[MX];
bool vis2[MX]; set<int> ss;



bool sub1(){
	FOR(i,0,N) FOR(j,0,N) if(p[i][j]!=1) return 0;
	return 1;
}

bool sub2(){
	FOR(i,0,N) FOR(j,i+1,N) if(i!=j) if(p[i][j]!=0 || p[i][j]!=1) return false;
	return true;
}
bool sub3(){
	FOR(i,0,N) FOR(j,i+1,N)if(i!=j) if(p[i][j]!=0 || p[i][j]!=2) return false;
	return true;
}


void dfs(int u){
	vis[u]=true;
	s.insert(u);
	for(auto v: adj[u]) if(!vis[v])dfs(v);
}
void dfs2(int u){
	vis2[u]=true;
	ss.insert(u);
	for(auto v: adj2[u]) if(!vis2[v])dfs2(v);
}

int construct(vector<vi> P) {
	N=sz(P[0]);
	vector<vi> res(N,vi(N,-1));
	FOR(i,0,N) FOR(j,0,N) p[i][j]=P[i][j],res[i][j]=0;

	if(sub1()){
		FOR(i,0,N-1) res[i][i+1]=res[i+1][i]=1;
	}
	else if(sub2()||sub3()){
		FOR(i,0,N) FOR(j,i+1,N) if(p[i][j]!=0){
			adj[i].pb(j); adj[j].pb(i);
		}
		FOR(i,0,N) vis[i]=false;
		FOR(i,0,N) if(!vis[i]){
			s.clear(); dfs(i);
			vi vec; for(auto x: s) vec.pb(x);
			if(sz(vec)==1) continue; //no edges to add
			//dbgv(vec);
			int cur=p[vec[0]][vec[1]];
			if(sz(vec)==2 && cur==2) return 0; //multiple edges
			FOR(j,0,sz(vec)) FOR(k,j+1,sz(vec)){
				if(p[vec[j]][vec[k]]!=cur) return 0;
			}
			FOR(i,0,sz(vec)){
				if(i<sz(vec)-1){
					res[vec[i]][vec[i+1]]=res[vec[i+1]][vec[i]]=1;
				}	
				if(i==sz(vec)-1 && cur==2) res[vec[i]][vec[0]]=res[vec[0]][vec[i]]=1;
			}
		}
	}
	else{
		FOR(i,0,N) FOR(j,i+1,N) if(p[i][j]!=0){
			adj[i].pb(j); adj[j].pb(i);
		}
		FOR(i,0,N) if(!vis[i]){
			s.clear(); dfs(i);
			vi vec; for(auto x: s) vec.pb(x);
			if(sz(vec)==1) continue; //no edges to add

			//We are in a connected component 
			
			FOR(j,0,sz(vec)) FOR(k,j+1,sz(vec)){
				if(p[vec[k]][vec[j]]==1){
					adj2[vec[k]].pb(vec[j]);
					adj2[vec[j]].pb(vec[k]);
				}
			}
			FOR(j,0,N) vis2[j]=false;

			vi cy;
			for(auto u: vec) if(!vis2[u]){
				ss.clear(); dfs2(u);
				vi vv; for(auto x: ss) vv.pb(x);
				cy.pb(u);
				if(sz(vv)==1) continue;
				FOR(i,0,sz(vv)-1){
					res[vv[i]][vv[i+1]]=res[vv[i+1]][vv[i]]=1;
				}
			}

			FOR(i,0,sz(cy)-1){
				res[cy[i]][cy[i+1]]=res[cy[i+1]][cy[i]]=1;
			}
			if(sz(cy)>1) res[cy.back()][cy[0]]=res[cy[0]][cy.back()]=1;

		}
	}

	build(res);

	return 1;
}

/*
5
0 0 0 0 0
0 0 2 2 2
0 2 0 2 2
0 2 2 0 2
0 2 2 2 0

0 0 0 0 0 
0 0 1 0 1 
0 1 0 1 0 
0 0 1 0 1 
0 1 0 1 0 
*/

/*
6
0 1 0 0 0 0
1 0 0 0 0 0
0 0 0 1 2 2
0 0 1 0 2 2
0 0 2 2 0 2
0 0 2 2 2 0

*/

/*
9
0 1 0 0 0 0 0 0 0
1 0 0 0 0 0 0 0 0
0 0 0 1 2 2 2 2 2
0 0 1 0 2 2 2 2 2
0 0 2 2 0 2 2 2 1
0 0 2 2 2 0 1 1 2
0 0 2 2 2 1 0 1 2
0 0 2 2 2 1 1 0 2
0 0 2 2 1 2 2 2 0


0 1 0 0 0 0 0 0 0 
1 0 0 0 0 0 0 0 0 
0 0 0 1 1 1 0 0 0 
0 0 1 0 0 0 0 0 0 
0 0 1 0 0 1 0 0 1 
0 0 1 0 1 0 1 0 0 
0 0 0 0 0 1 0 1 0 
0 0 0 0 0 0 1 0 0 
0 0 0 0 1 0 0 0 0 
*/




/* Careful!!!
	.Array bounds
	.Infinite loops
	.Uninitialized variables / empty containers
	.Order of input

   Some insights:
	.Binary search
	.Graph representation
	.Write brute force code
	.Change your approach
*/

Compilation message (stderr)

supertrees.cpp:4: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
    4 | #pragma GCC optimization ("O3")
      | 
supertrees.cpp:5: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
    5 | #pragma GCC optimization ("unroll-loops")
      | 
supertrees.cpp: In function 'void IO()':
supertrees.cpp:51:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   51 |  freopen("input.txt", "r", stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
supertrees.cpp:52:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   52 |  freopen("output.txt", "w", stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 0 / 10
• Subtask 3: 0 / 19
• Subtask 4: 35 / 35
• Subtask 5: 0 / 21
• Subtask 6: 0 / 4