Submission #432951

#	Time	Username	Problem	Language	Result	Execution time	Memory
432951		jeroenodb	Data Transfer (IOI19_transfer)	C++14	100 / 100	223 ms	2508 KiB

transfer

#ifndef GRADER
#include "transfer.h"
#endif
#include "bits/stdc++.h"
using namespace std;
#define all(x) begin(x),end(x)
template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; }
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { string sep; for (const T &x : v) os << sep << x, sep = " "; return os; }
#define debug(a) cerr << "(" << #a << ": " << a << ")\n";
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int,int> pi;
vi get_attachment(vi source) {
	auto n = source.size();
	vi output;
	int last=0;
	for(int i=0;(1<<i)<n;++i) {
		output.push_back(0);
		for(int j=0;j<n;++j) {
			if((j&(1<<i))==0)
				output.back()^=source[j];
		}
		last^=output.back();
	}
	output.push_back(last);
	return output;
}

std::vector<int> retrieve(vi data) {
	int k=__lg(data.size());
	int n = (1<<k) -1;
	vi extra(data.begin()+n,data.end());
	data.erase(data.begin()+n,data.end());
	int check=0;
	for(int i: extra) check^=i;
	if(check) return data;
	extra.pop_back();
	int wrong = 0;
	for(int i=0;(1<<i) < n;++i) {
		check=extra[i];
		for(int j=0;j<n;++j) {
			if((j&(1<<i))==0)
				check^=data[j];
		}
		if(!check) wrong+=(1<<i);
	}
	if(wrong<data.size()) {
		data[wrong]^=1;
	}
	return data;

}

Compilation message (stderr)

transfer.cpp: In function 'vi get_attachment(vi)':
transfer.cpp:18:20: warning: comparison of integer expressions of different signedness: 'int' and 'long unsigned int' [-Wsign-compare]
   18 |  for(int i=0;(1<<i)<n;++i) {
      |              ~~~~~~^~
transfer.cpp:20:16: warning: comparison of integer expressions of different signedness: 'int' and 'long unsigned int' [-Wsign-compare]
   20 |   for(int j=0;j<n;++j) {
      |               ~^~
transfer.cpp: In function 'std::vector<int> retrieve(vi)':
transfer.cpp:48:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   48 |  if(wrong<data.size()) {
      |     ~~~~~^~~~~~~~~~~~

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