Submission #1061206

#	Time	Username	Problem	Language	Result	Execution time	Memory
1061206		boyliguanhan	Martian DNA (IOI16_dna)	C++17	100 / 100	6 ms	520 KiB

dna

#include "dna.h"
#include <bits/stdc++.h>
using namespace std;
mt19937 rng(2893478);
int bad_streak;
string analyse(int n, int t) {
    string str="1";
    while(1){
        char c='0'+rng()%2;
        char oth=(c=='0'?'1':'0');
        if(make_test(str+c))
            str+=c,bad_streak=0;
        else str+=oth,
            bad_streak++;
        if(bad_streak==18){
            if(make_test(str))continue;
            int l=str.size()-18,r=str.size()-1,res=str.size()-1;
            while(l<=r){
                int mid=l+r>>1;
                if(make_test(str.substr(0,mid)))
                    l=mid+1;
                else res=mid,r=mid-1;
            }
            str.erase(str.begin()+res-1,str.end());
            break;
        }
    }
    while(str.size()<n){
        char c='0'+rng()%2;
        char oth=(c=='0'?'1':'0');
        if(make_test(c+str))
            str=c+str;
        else str=oth+str;
    }
    return str;
}

Compilation message (stderr)

dna.cpp: In function 'std::string analyse(int, int)':
dna.cpp:19:26: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   19 |                 int mid=l+r>>1;
      |                         ~^~
dna.cpp:28:21: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   28 |     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