Submission #515989

#	Time	Username	Problem	Language	Result	Execution time	Memory
515989		jk410	Martian DNA (IOI16_dna)	C++17	100 / 100	13 ms	380 KiB

dna

#include <bits/stdc++.h>
#include "dna.h"
using namespace std;
string analyse(int n,int t) {
    string s;
    if (!make_test("0")){
        for (int i=0; i<n; i++)
            s.push_back('1');
        return s;
    }
    for (int i=0; i<n; i++)
        s.push_back('0');
    int l=1,r=n,len;
    while (l<=r){
        int m=(l+r)/2;
        if (make_test(s.substr(0,m))){
            len=m;
            l=m+1;
        }
        else
            r=m-1;
    }
    s=s.substr(0,len);
    for (int cnt=0; cnt<=len;){
        if (make_test(s+"1")){
            s.push_back('1');
            cnt=0;
        }
        else{
            s.push_back('0');
            cnt++;
        }
    }
    l=1;
    r=(int)s.length();
    while (l<=r){
        int m=(l+r)/2;
        if (make_test(s.substr(0,m))){
            len=m;
            l=m+1;
        }
        else
            r=m-1;
    }
    s=s.substr(0,len);
    while (len<n){
        if (make_test("0"+s))
            s="0"+s;
        else
            s="1"+s;
        len++;
    }
    return s;
}

Compilation message (stderr)

dna.cpp: In function 'std::string analyse(int, int)':
dna.cpp:24:24: warning: 'len' may be used uninitialized in this function [-Wmaybe-uninitialized]
   24 |     for (int cnt=0; cnt<=len;){
      |                     ~~~^~~~~
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