Submission #330483

#	Time	Username	Problem	Language	Result	Execution time	Memory
330483		aquablitz11	Mechanical Doll (IOI18_doll)	C++14	100 / 100	139 ms	9936 KiB

doll

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

const int INF = 2e9;

vector<int> C, X, Y;
int cnt = 0;

int get_switch(int x, int y) {
    X.push_back(x);
    Y.push_back(y);
    return --cnt;
}

int create_tree(const vector<int> &v) {
    bool ok = true;
    for (int i = 0; i < (int)v.size()-1; ++i) {
        if (v[i] != v[i+1])
            ok = false;
    }
    if (ok)
        return v[0];
    vector<int> vx, vy;
    for (int i = 0; i < v.size(); ++i) {
        if (i % 2 == 0)
            vx.push_back(v[i]);
        else
            vy.push_back(v[i]);
    }
    int x = create_tree(vx);
    int y = create_tree(vy);
    return get_switch(x, y);
}

int reverse_bit(int k, int a) {
    int b = 0;
    while (k--) {
        b <<= 1;
        b |= (a&1);
        a >>= 1;
    }
    return b;
}

void create_circuit(int M, vector<int> A) {

    // find k
    int n = A.size();
    int k = 0;
    while ((1<<k) < n)
        ++k;

    vector<int> v(1<<k, 0);
    for (int i = 0; i < (1<<k)-n; ++i)
        v[reverse_bit(k, i)] = INF;

    int cnt = 0;
    for (int i = 1; i < n; ++i) {
        while (cnt < v.size() && v[cnt] != 0) ++cnt;
        v[cnt] = A[i];
    }

    n = 1<<k;
    v[n-1] = 0;
    int r = create_tree(v);
    C = vector<int>(M+1, r);
    C[0] = A[0];
    for (auto &x: X) {
        if (x == INF)
            x = r;
    }
    for (auto &y: Y) {
        if (y == INF)
            y = r;
    }
    answer(C, X, Y);
}

Compilation message (stderr)

doll.cpp: In function 'int create_tree(const std::vector<int>&)':
doll.cpp:25:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 |     for (int i = 0; i < v.size(); ++i) {
      |                     ~~^~~~~~~~~~
doll.cpp: In function 'void create_circuit(int, std::vector<int>)':
doll.cpp:60:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   60 |         while (cnt < v.size() && v[cnt] != 0) ++cnt;
      |                ~~~~^~~~~~~~~~

• Subtask 1: 2 / 2
• Subtask 2: 4 / 4
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 18 / 18
• Subtask 6: 56 / 56