Submission #285087

#	Time	Username	Problem	Language	Result	Execution time	Memory
285087		Berted	Unscrambling a Messy Bug (IOI16_messy)	C++14	100 / 100	3 ms	512 KiB

messy

#include <vector>
#include <iostream>
#include <assert.h>

#include "messy.h"

using namespace std;

string start;
vector<int> ans, ans2;

void flip(string& s, int i) {s[i] = ((s[i] - '0') ^ 1) + '0';}

void ask(int L, int R, string s)
{
	if (L < R)
	{
		int M = L + R >> 1;
		for (int i = M + 1; i <= R; i++)
		{
			flip(s, i);
			add_element(s);
			flip(s, i);
		}
		for (int i = M + 1; i <= R; i++) {flip(s, i);}
		ask(L, M, s); 
		for (int i = L; i <= R; i++) {flip(s, i);}
		ask(M + 1, R, s);
	}
}

void solve(int L, int R, string s)
{
	if (L < R)
	{
		int M = L + R >> 1, idx = L;
		for (int i = L; i <= R; i++)
		{
			flip(s, ans[i]);
			if (!check_element(s)) {flip(s, ans[i]); swap(ans[i], ans[idx++]);}
			else {flip(s, ans[i]);}
		}
		assert(idx == M + 1);
		for (int i = M + 1; i <= R; i++) {flip(s, ans[i]);}
		solve(L, M, s); 
		for (int i = L; i <= R; i++) {flip(s, ans[i]);}
		solve(M + 1, R, s);
	}
}

vector<int> restore_permutation(int n, int w, int r) 
{
    for (int i = 0; i < n; i++) {start.push_back('0'); ans.push_back(i); ans2.push_back(0);}
    ask(0, n - 1, start);
	compile_set();
	solve(0, n - 1, start);
	for (int i = 0; i < ans.size(); i++) {ans2[ans[i]] = i;}
	return ans2;
}

Compilation message (stderr)

messy.cpp: In function 'void ask(int, int, std::string)':
messy.cpp:18:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   18 |   int M = L + R >> 1;
      |           ~~^~~
messy.cpp: In function 'void solve(int, int, std::string)':
messy.cpp:36:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   36 |   int M = L + R >> 1, idx = L;
      |           ~~^~~
messy.cpp: In function 'std::vector<int> restore_permutation(int, int, int)':
messy.cpp:57:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |  for (int i = 0; i < ans.size(); i++) {ans2[ans[i]] = i;}
      |                  ~~^~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 18 / 18
• Subtask 3: 11 / 11
• Subtask 4: 21 / 21
• Subtask 5: 30 / 30