Submission #916662

#	Time	Username	Problem	Language	Result	Execution time	Memory
916662		Wansur	Parrots (IOI11_parrots)	C++14	52 / 100	2102 ms	15508 KiB

encoder

#include <bits/stdc++.h>
#define f first
#define s second
#define ent '\n';

using namespace std;
typedef long long ll;
const int mx=2e5+12;

void output(int b);
void send(int a);

vector<int> g[mx];
int cnt[mx];
int p[mx];


void encode(int n, int a[]){
	mt19937 rnd(228);
	for(int i=0;i<n;i++){
		send(a[i]);
		for(int t=0;t<9;t++){
			int x=rnd()%256;
			send((a[i]^x));
		}
	}
}

decoder

#include <bits/stdc++.h>
#define f first
#define s second
#define ent '\n';

using namespace std;
typedef long long ll;
const int mx=2e5+12;

void output(int b);
void send(int a);

vector<int> g[mx];
int cnt[mx];
int p[mx];

void decode(int m, int n, int a[]){
	sort(a,a+n);
	for(int i=0;i<256;i++){
		cnt[i]=0;
		g[i].clear();
	}
	for(int i=0;i<n;i++){
		cnt[a[i]]++;
	}
	mt19937 rnd(228);
	for(int i=0;i<m;i++){
		p[i]=i;
		for(int t=0;t<9;t++){
			int x=rnd()%256;
			g[i].push_back(x);
		}
	}
	while(1){
		for(int i=0;i<256;i++){
			cnt[i]=0;
		}
		for(int i=0;i<n;i++){	
			cnt[a[i]]++;
		}
		for(int i=0;i<m;i++){
			swap(p[i],p[rnd()%m]);
		}
		vector<pair<int,int>> d;
		for(int i=0;i<n;i++){
			vector<int> v=g[p[i]];
			for(int x=0;x<=256;x++){
				vector<int> t={x};
				int mn=--cnt[x];
				for(int y:v){
					mn=min(mn,--cnt[(x^y)]);
					t.push_back((x^y));
				}
				if(mn>=0){
					d.push_back({p[i],x});
					break;
				}
				for(int x:t){
					cnt[x]++;
				}
			}
		}
		if(d.size()==m){
			sort(d.begin(),d.end());
			for(auto x:d){
				output(x.s);
			}
			return;
		}
	}
}

Compilation message (stderr)

decoder.cpp: In function 'void decode(int, int, int*)':
decoder.cpp:63:14: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   63 |   if(d.size()==m){
      |      ~~~~~~~~^~~

• Subtask 1: 17 / 17
• Subtask 2: 17 / 17
• Subtask 3: 18 / 18
• Subtask 4: 0 / 29
• Subtask 5: 0 / 19