Submission #521467

#	Time	Username	Problem	Language	Result	Execution time	Memory
521467		Joo	Martian DNA (IOI16_dna)	C++17	100 / 100	13 ms	380 KiB

dna

#include "dna.h"

#include <bits/stdc++.h>
#include <cstdlib>
using namespace std;

std::string analyse(int n, int t) {
    if(!make_test("0")) return string(n, '1');

    string str(n, '0');
    int l = 1, r = n, longest_zero = -1;
    while(l <= r){
        int mid = (l+r)>>1;
        if(make_test(str.substr(0, mid))){
            longest_zero = mid;
            l = mid+1;
        } else {
            r = mid-1;
        }
    }
    assert(longest_zero != -1);

    str = str.substr(0, longest_zero);
    int cntz = longest_zero;
    while(str.size() < n){
        if(make_test(str+"1")){
            str += "1";
            cntz = 0;
        } else {
            cntz++;
            if(cntz > longest_zero){
                break;
            }
            str += "0";
        } 
    }

    l = 0, r = str.size()-longest_zero;
    int endpoint = -1;
    while(l <= r){
        int mid = (l+r)>>1;
        if(make_test(str.substr(0, longest_zero+mid))){
            endpoint = longest_zero+mid;
            l = mid+1;
        } else {
            r = mid-1;
        }
    }

    str = str.substr(0, endpoint);
    while(str.size() < n){
        if(make_test("1"+str)){
            str = "1" + str;
        } else {
            str = "0" + str;
        }
    }

    return str;
}                       

Compilation message (stderr)

dna.cpp: In function 'std::string analyse(int, int)':
dna.cpp:25:22: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   25 |     while(str.size() < n){
      |           ~~~~~~~~~~~^~~
dna.cpp:51:22: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   51 |     while(str.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