Submission #747716

#	Time	Username	Problem	Language	Result	Execution time	Memory
747716		_martynas	Unscrambling a Messy Bug (IOI16_messy)	C++11	100 / 100	2 ms	496 KiB

messy

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

using namespace std;

#define PB push_back

using vi = vector<int>;

struct Group {
    vi from, to;
};

vi restore_permutation(int n, int w, int r) {
    /*
    add_element("0");
    compile_set();
    check_element("0");
    */
    int B = __builtin_ctz(n);
    for(int b = B; b >= 1; b--) {
        for(int i = 0; i < n; i += 1<<b) {
            for(int j = i; j < i+(1<<b)/2; j++) {
                string s(n, '1');
                fill(s.begin()+i, s.begin()+i+(1<<b), '0');
                s[j] = '1';
                add_element(s);
            }
        }
    }
    compile_set();
    vector<Group> G;
    {
        Group g;
        for(int i = 0; i < n; i++) g.from.PB(i), g.to.PB(i);
        G.PB(g);
    }
    for(int b = B; b >= 1; b--) {
        vector<Group> Gp;
        for(auto g : G) {
            // from should be consecutive positions
            vi set_bits, unset_bits;
            for(int i : g.to) {
                string s(n, '1');
                for(int j : g.to) s[j] = '0';
                s[i] = '1';
                bool resp = check_element(s);
                if(resp) {
                    set_bits.PB(i);
                }
                else {
                    unset_bits.PB(i);
                }
            }
            Group gl, gr;
            for(int i = 0; i < g.from.size(); i++) {
                if(i < g.from.size()/2) {
                    gl.from.PB(g.from[i]);
                    gl.to.PB(set_bits[i]);
                }
                else {
                    gr.from.PB(g.from[i]);
                    gr.to.PB(unset_bits[i - g.from.size()/2]);
                }
            }
            Gp.PB(gl); Gp.PB(gr);
        }
        G = Gp;
    }
    vi ans(n);
    for(int i = 0; i < n; i++) {
        ans[G[i].to[0]] = G[i].from[0];
    }
    return ans;
}
/*
4 100 100 2 1 3 0


*/

Compilation message (stderr)

messy.cpp: In function 'vi restore_permutation(int, int, int)':
messy.cpp:56:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |             for(int i = 0; i < g.from.size(); i++) {
      |                            ~~^~~~~~~~~~~~~~~
messy.cpp:57:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |                 if(i < g.from.size()/2) {
      |                    ~~^~~~~~~~~~~~~~~~~

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