Submission #409907

#	Time	Username	Problem	Language	Result	Execution time	Memory
409907		Alma	Martian DNA (IOI16_dna)	C++17	100 / 100	14 ms	404 KiB

dna

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

string analyse(int n, int t) {
    string z = "", o = "";
    for (int i = 0; i < n; i++) {
        z += '0'; o += '1';
    }
    if (!make_test("0")) return o;

    string p;
    int lo = 1, mid, max0 = n, hi = n;
    while (lo <= hi) {
        mid = (lo+hi) / 2;
        p = z.substr(0, mid);
        if (make_test(p)) {
            max0 = mid;
            lo = mid+1;
        } else {
            hi = mid-1;
        }
    }
    p = z.substr(0, max0);
    int l = max0, r = max0;
    while (r <= max0) {
        if (make_test(p + '1')) {
            p += '1'; r = 0;
        } else {
            p += '0'; r++;
        }
    }
    int rest;
    string s;
    lo = max0; hi = n;
    while (lo <= hi) {
        mid = (lo+hi) / 2;
        s = p.substr(0, mid);
        if (make_test(s)) {
            rest = mid;
            lo = mid+1;
        } else {
            hi = mid-1;
        }
    }
    s = p.substr(0, rest);
    for (int i = rest; i < n; i++) {
        if (l >= max0 || make_test('1' + s)) {
            s = '1' + s; l = 0;
        } else {
            s = '0' + s; l++;
        }
    }
    return s;
}

Compilation message (stderr)

dna.cpp: In function 'std::string analyse(int, int)':
dna.cpp:46:25: warning: 'rest' may be used uninitialized in this function [-Wmaybe-uninitialized]
   46 |     s = p.substr(0, rest);
      |                         ^
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