Submission #582726

#	Time	Username	Problem	Language	Result	Execution time	Memory
582726		SlavicG	Unscrambling a Messy Bug (IOI16_messy)	C++17	100 / 100	2 ms	468 KiB

messy

#include "bits/stdc++.h"
#include "messy.h"

using namespace std;

const int N = 128;
vector<int> p;
void build(int l, int r, int n) {
    if(l == r) return;
    int mid = l + r >> 1;
    string s(n, '0');
    for(int i = 0; i < l; ++i) s[i] = '1';
    for(int i = r + 1; i < n; ++i) s[i] = '1';

    for(int i = l; i <= mid; ++i) {
        s[i] = '1';
        add_element(s);
        s[i] = '0';
    }
    build(l, mid, n);
    build(mid + 1, r, n);
}

void rec(int l, int r, vector<int> responsible, int n) {
    assert(responsible.size() == r - l + 1);
    if(l == r) {
        assert(responsible.size() == 1);
        p[responsible[0]] = l;
        return;
    }

    int mid = l + r >> 1;
    string s(n, '1');
    for(auto x: responsible) s[x] = '0';
    vector<int> v1, v2;
    for(int i = 0; i < n; ++i) {
        if(s[i] == '0') {
            s[i] = '1';
            if(check_element(s)) {
                v1.push_back(i);
            } else v2.push_back(i);
            s[i] = '0';
        }
    }
    rec(l, mid, v1, n);
    rec(mid + 1, r, v2, n);
}

std::vector<int> restore_permutation(int n, int w, int r) {
    build(0, n - 1, n);
    compile_set();
    p.assign(n, -1);
    vector<int> paiu(n);
    iota(paiu.begin(),paiu.end(), 0);
    rec(0, n - 1, paiu, n);
    return p;
}

Compilation message (stderr)

messy.cpp: In function 'void build(int, int, int)':
messy.cpp:10:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   10 |     int mid = l + r >> 1;
      |               ~~^~~
In file included from /usr/include/c++/10/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:33,
                 from messy.cpp:1:
messy.cpp: In function 'void rec(int, int, std::vector<int>, int)':
messy.cpp:25:31: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   25 |     assert(responsible.size() == r - l + 1);
      |            ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~
messy.cpp:32:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   32 |     int mid = l + r >> 1;
      |               ~~^~~

• Subtask 1: 20 / 20
• Subtask 2: 18 / 18
• Subtask 3: 11 / 11
• Subtask 4: 21 / 21
• Subtask 5: 30 / 30