Submission #285019

#	Time	Username	Problem	Language	Result	Execution time	Memory
285019		user202729	Unscrambling a Messy Bug (IOI16_messy)	C++17	100 / 100	3 ms	640 KiB

messy

// moreflags=grader.cpp
#include <vector>
// 15
// (somehow the wrong solution breaks at the sample solution... and I didn't notice it!?)

#include "messy.h"
#if not LOCAL
#define NDEBUG 1
#endif
#include<cassert>

template<bool write> std::vector<int> process(int n, std::vector<int> a, std::vector<int> pivot){
	auto const sizea=(int)a.size();
	auto const numBit=__builtin_ctz(sizea);
	assert(sizea==(1<<numBit));

	if(sizea==1) return a;
	auto const half=sizea>>1;
	if(write){
		std::vector<int> first(a.begin(), a.begin()+half), sec(a.begin()+half, a.end());
		for(auto it: first){
			std::string tmp(n,'0');
			for(auto it: pivot) tmp[it]='1';
			tmp[it]='1';
			add_element(std::move(tmp));
		}

		process<true>(n, first, sec);
		process<true>(n, sec, first);
		return {};
	}else{
		std::vector<int> first, sec;
		for(auto it: a){
			std::string tmp(n,'0');
			for(auto it: pivot) tmp[it]='1';
			tmp[it]='1';
			if(check_element(std::move(tmp)))
				first.push_back(it);
			else
				sec.push_back(it);
		}
		assert((int)first.size()==half);
		assert((int)sec.size()==half);

		auto result=process<false>(n, first, sec);
		auto result2=process<false>(n, sec, first);
		result.insert(result.end(),begin(result2), end(result2));
		return result;
	}
}

std::vector<int> restore_permutation(int n, int w, int r) {
	std::vector<int> all(n);
	for(int i=0; i<n; ++i) all[i]=i;
	process<true>(n, all,{});
	compile_set();
	auto const result1=process<false>(n, std::move(all),{});
	std::vector<int> result(n);
	for(int index=0; index<n; ++index)
		result[result1[index]]=index;
	return result;
}

Compilation message (stderr)

messy.cpp: In instantiation of 'std::vector<int> process(int, std::vector<int>, std::vector<int>) [with bool write = true]':
messy.cpp:55:25:   required from here
messy.cpp:14:13: warning: unused variable 'numBit' [-Wunused-variable]
   14 |  auto const numBit=__builtin_ctz(sizea);
      |             ^~~~~~
messy.cpp: In instantiation of 'std::vector<int> process(int, std::vector<int>, std::vector<int>) [with bool write = false]':
messy.cpp:57:56:   required from here
messy.cpp:14:13: warning: unused variable 'numBit' [-Wunused-variable]

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