Submission #782020

#	Time	Username	Problem	Language	Result	Execution time	Memory
782020		Dan4Life	Data Transfer (IOI19_transfer)	C++17	0 / 100	4 ms	2496 KiB

transfer

#include <bits/stdc++.h>
using namespace std;
using vi=vector<int>;
#define sz(a) a.size()
 
vi get_attachment(vi v) {
	int x = 0, y = 0; vi a;
	for(int i = 0; i < sz(v); i++) if(v[i]) x^=i+1;
	for(int i = 0; i < __lg(sz(v)+1); i++) a.push_back((x>>i)&1), y^=(x>>i)&1;
	a.push_back(y); return a;
}
 
vi retrieve(vi v){
	int x = 0, xx = 0, y = 0, n=sz(v)<99?63:255;
	for(int i = 0; i < n; i++) if(v[i]) x^=i+1;
	for(int i = 0; i < __lg(n+1); i++) if(v[n+i]) xx^=1<<i, y^=1;
	if(v.back()==y and x^xx) v[x^xx-1]^=1; return vi(begin(v),begin(v)+n);
}

Compilation message (stderr)

transfer.cpp: In function 'vi get_attachment(vi)':
transfer.cpp:8:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    8 |  for(int i = 0; i < sz(v); i++) if(v[i]) x^=i+1;
      |                   ^
transfer.cpp:9:19: warning: comparison of integer expressions of different signedness: 'int' and 'long unsigned int' [-Wsign-compare]
    9 |  for(int i = 0; i < __lg(sz(v)+1); i++) a.push_back((x>>i)&1), y^=(x>>i)&1;
      |                 ~~^~~~~~~~~~~~~~~
transfer.cpp: In function 'vi retrieve(vi)':
transfer.cpp:17:33: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
   17 |  if(v.back()==y and x^xx) v[x^xx-1]^=1; return vi(begin(v),begin(v)+n);
      |                               ~~^~
transfer.cpp:17:2: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   17 |  if(v.back()==y and x^xx) v[x^xx-1]^=1; return vi(begin(v),begin(v)+n);
      |  ^~
transfer.cpp:17:41: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   17 |  if(v.back()==y and x^xx) v[x^xx-1]^=1; return vi(begin(v),begin(v)+n);
      |                                         ^~~~~~

• Subtask 1: 0 / 60
• Subtask 2: 0 / 40