Submission #432800

#	Time	Username	Problem	Language	Result	Execution time	Memory
432800		amunduzbaev	Martian DNA (IOI16_dna)	C++14	100 / 100	14 ms	384 KiB

dna

#include "dna.h"
#ifndef EVAL
#include "grader.cpp"
#endif
#include "bits/stdc++.h"
using namespace std;

#define sz(x) (int)x.size()

//~ int n;

string make_str(int bit, int len){
	string ss;
	for(int i=0;i<len;i++) ss = ss + char(bit + '0');
	return ss;
}

bool ask(int bit, int len) { return make_test(make_str(bit, len)); }

/*

00110
10110
11011

*/

string analyse(int N, int t) {
	//~ n = N;
	int n = N;
	int l = 1, r = n;
	int bit = 1;
	if(!make_test("1")) bit = 0;
	while(l < r){
		int m = (l + r + 1)>>1;
		if(ask(bit, m)) l = m;
		else r = m - 1;
	}
	
	int len = l;
	string ss;
	for(int i=0;i<len;i++) ss = ss + char(bit + '0'); 
	
	//~ cout<<ss<<"\n";
	
	if(make_test(string(ss + char((bit ^ 1) + '0')))){
		int last = 0;
		ss += char((bit ^ 1) + '0');
		while(sz(ss) < n && last <= len){
			if(make_test(string(ss + char((bit ^ 1) + '0')))) ss += char((bit ^ 1) + '0'), last = 0;
			else ss += char(bit + '0'), last++;
		} 
		
		//~ cout<<ss<<"\n";
		
		int l = 0, r = 0;
		while(!ss.empty() && ss.back() == char(bit + '0')) ss.pop_back(), r++;
		//~ if(r > len) r = len;
		
		//~ cout<<ss<<"\n";
		
		//~ int l = 0, r = len;
		while(l + 1 < r){
			int m = (l + r)>>1;
			if(make_test(string(ss + make_str(bit, m)))) l = m;
			else r = m;
		} 
		
		if(make_test(string(ss + make_str(bit, r)))) ss += make_str(bit, r);
		else ss += make_str(bit, l);
		
		//~ cout<<ss<<"\n";
	}
	
	while(sz(ss) < n){
		if(make_test(string(char((bit ^ 1) + '0') + ss))) ss = char((bit ^ 1) + '0') + ss;
		else ss = char(bit + '0') + ss;
	} return ss;
}

/*

00000
00001
00010
00011
00100
00101
00

*/

Compilation message (stderr)

grader.cpp: In function 'bool make_test(std::string)':
grader.cpp:14:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 |  for (int i = 0; i < p.size(); i++) {
      |                  ~~^~~~~~~~~~
grader.cpp:23:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |  for (int i = 1; i <= ss.size(); i++) {
      |                  ~~^~~~~~~~~~~~
grader.cpp:28:13: warning: comparison of integer expressions of different signedness: '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'} and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |   if (pr[i] == p.size()) {

• Subtask 1: 11 / 11
• Subtask 2: 25 / 25
• Subtask 3: 64 / 64