Submission #882290

#	Time	Username	Problem	Language	Result	Execution time	Memory
882290		pirhosig	Martian DNA (IOI16_dna)	C++17	100 / 100	10 ms	608 KiB

dna

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



string analyse(int n, int t)
{
    string res;
    if (n < 500)
    {
        bool forward = true;
        for (int i = 0; i < n; ++i)
        {
            if (forward)
            {
                if (make_test(res + '0')) res += '0';
                else if (make_test(res + '1')) res += '1';
                else forward = false;
            }
            if (!forward)
            {
                res.insert(0, 1, '0');
                if (!make_test(res)) res[0] = '1';
            }
        }
    }
    else
    {
        int len = 0;
        int val = 0;
        while (val < n) {
            if (rand() % 2) {
                res.append("0");
                if (make_test(res)) len = val;
                else res.back() = '1';
            }
            else {
                res.append("1");
                if (make_test(res)) len = val;
                else res.back() = '0';
            }
            val++;
            if (val - len == 11) {
                bool full = true;
                while (len < val) {
                    int mid = (len + val + 1) / 2;
                    if (make_test(res.substr(0, mid))) len = mid;
                    else {
                        for (int i = 0; i <= val - mid; ++i) res.pop_back();
                        val = mid - 1;
                        goto end;
                    }
                }
            }
        }
        end:
        while (len < val) {
            int mid = (len + val + 1) / 2;
            if (make_test(res.substr(0, mid))) len = mid;
            else {
                for (int i = 0; i <= val - mid; ++i) res.pop_back();
                val = mid - 1;
            }
        }
        while (len < n) {
            res.insert(0, 1, '0');
            if (!make_test(res)) res[0] = '1';
            len++;
        }
    }

    return res;
}               

Compilation message (stderr)

dna.cpp: In function 'std::string analyse(int, int)':
dna.cpp:45:22: warning: unused variable 'full' [-Wunused-variable]
   45 |                 bool full = true;
      |                      ^~~~
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