Submission #211907

#	Time	Username	Problem	Language	Result	Execution time	Memory
211907		MarcoMeijer	Data Transfer (IOI19_transfer)	C++14	100 / 100	211 ms	2860 KiB

transfer

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

//macros
typedef long long ll;
typedef pair<int, int> ii;
typedef tuple<int, int, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<iii> viii;
typedef vector<ll> vll;
#define REP(a,b,c) for(int a=int(b); a<int(c); a++)
#define RE(a,c) REP(a,0,c)
#define RE1(a,c) REP(a,1,c+1)
#define REI(a,b,c) REP(a,b,c+1)
#define REV(a,b,c) for(int a=int(c-1); a>=int(b); a--)
#define INF 1e9
#define pb push_back
#define fi first
#define se second
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

vi get_attachment(vi source) {
	vi ans;
	RE(bits,20) {
		int stepSize = (1<<bits);
		bool p=0;
		if(stepSize > source.size()) {
			RE(i,ans.size()) p ^= ans[i];
			ans.pb(p);
			return ans;
		}
		RE(j,source.size()) if((j+1)&stepSize) p^=source[j];
		ans.pb(p);
	}
}

vi retrieve(vi data) {
	int n=63;
	if(data.size() > 100) n=255;
	int expected=0;
	int reality=0;
	bool endCorrupt=0;
	RE(bits,20) {
		int stepSize = (1<<bits);
		bool p=0;
		if(stepSize > n) {
			REP(i,n,data.size()-1) p ^= data[i];
			if(p != data.back()) endCorrupt=1;
			break;
		}
		RE(j,n) if((j+1)&stepSize) p^=data[j];
		if(p) expected += stepSize;
		if(data[n+bits]) reality += stepSize;
	}
	if(!endCorrupt && reality!=expected) {
		int change=reality^expected;
		change--;
		data[change] ^= 1;
	}
	while(data.size() > n) data.pop_back();
	return data;
}

Compilation message (stderr)

transfer.cpp: In function 'vi get_attachment(vi)':
transfer.cpp:29:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(stepSize > source.size()) {
      ~~~~~~~~~^~~~~~~~~~~~~~~
transfer.cpp: In function 'vi retrieve(vi)':
transfer.cpp:62:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while(data.size() > n) data.pop_back();
        ~~~~~~~~~~~~^~~
transfer.cpp: In function 'vi get_attachment(vi)':
transfer.cpp:37:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^

• Subtask 1: 60 / 60
• Subtask 2: 40 / 40