Submission #382063

#	Time	Username	Problem	Language	Result	Execution time	Memory
382063		ritul_kr_singh	Martian DNA (IOI16_dna)	C++17	100 / 100	15 ms	512 KiB

dna

#include "dna.h"
#include "bits/stdc++.h"
using namespace std;
#define sp << " " <<
#define nl << "\n"
 
string create(string i, int j){
	string res;
	while(j--) res += i;
	return res;
}
 
string analyse(int n, int t){
	string ans;
	if(!make_test("1")){
		return create("0", n);
	}
 
	int low = 1, high = n;
	while(low<high){
		int mid = (low+high)/2;
		if(make_test(create("1", mid+1))) low = mid+1;
		else high = mid;
	}
  	ans = create("1", low);
 
	int prevOnes = high, maxOnes = high;
	bool backward = false;
	while(!(backward and ans.size()==n)){
		if(backward){
			if(make_test("0"+ans)) ans = "0"+ans;
			else ans = "1"+ans;
		}else{
			if(make_test(ans+"0")) ans += "0", prevOnes = 0;
			else{
				ans += "1";
				++prevOnes;
				if(prevOnes>maxOnes){ // found endpoint
					string temp; swap(temp, ans);
					for(int i=0; i+maxOnes+1<(int)temp.size(); ++i) ans.push_back(temp[i]);
 
 
					low = 0, high = maxOnes;
					while(low<high){
						int mid = (low+high)/2;
						if(make_test(ans+create("1", mid+1))) low = mid+1;
						else high = mid;
					}
					ans += create("1", low);
					backward = true;
				}
			}
		}
	}
	return ans;
}

Compilation message (stderr)

dna.cpp: In function 'std::string analyse(int, int)':
dna.cpp:29:33: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   29 |  while(!(backward and ans.size()==n)){
      |                       ~~~~~~~~~~^~~
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