Submission #592825

#	Time	Username	Problem	Language	Result	Execution time	Memory
592825		tarche	Martian DNA (IOI16_dna)	C++17	100 / 100	13 ms	468 KiB

dna

#include "dna.h"

#include <bits/stdc++.h>

using namespace std;

int lengthLongestZeroChain(int n) {
  int low = 0, high = n;
  while (low + 1 < high) {
    int mid = (low + high) / 2;
    string s(mid, '0');
    if (make_test(s)) {
      low = mid;
    } else {
      high = mid;
    }
  }

  return low;
}

void findStringEnding(string& s, string& chain) {
  int n = (int)chain.length();
  int low = 0, high = n;
  while (low + 1 < high) {
    int mid = (low + high) / 2;
    chain = string(mid, '0');
    if (make_test(s + chain)) {
      low = mid;
    } else {
      high = mid;
    }
  }

  s += string(low, '0');
}

void growSubstringRight(string& s, string& chain) {
  if (make_test(s + chain + '1')) {
    s += chain + '1';
    chain = "";
  } else {
    chain += '0';
  }
}

void growSubstringLeft(string& s) {
  if (make_test('1' + s)) {
    s = "1" + s;
  } else {
    s = "0" + s;
  }
}

string analyse(int n, int t) {
  int zeroChainLen = lengthLongestZeroChain(n);
  string curr(zeroChainLen, '0'), chain = "";
  while ((int)chain.length() <= zeroChainLen && (int)curr.length() < n) {
    growSubstringRight(curr, chain);
  }

  findStringEnding(curr, chain);

  while ((int)curr.length() < n) {
    growSubstringLeft(curr);
  }

  return curr;
}

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