Submission #805026

#	Time	Username	Problem	Language	Result	Execution time	Memory
805026		PixelCat	Counting Mushrooms (IOI20_mushrooms)	C++14	56.64 / 100	11 ms	392 KiB

mushrooms

#include "mushrooms.h"

#ifdef NYAOWO
#include "stub.cpp"
#endif

#include <bits/stdc++.h>
#define For(i, a, b) for(int i = a; i <= b; i++)
#define Forr(i, a, b) for(int i = a; i >= b; i--)
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define sz(x) ((int)x.size())
#define eb emplace_back
// #define int LL
using namespace std;
using i32 = int32_t;
using LL = long long;
using pii = pair<int, int>;

int SQ = 100;

int alter(vector<int> jury, vector<int> sus, bool flip) {
    assert(sz(jury) > sz(sus));
    vector<int> q;
    int n = sz(sus);
    q.eb(jury.back()); jury.pop_back();
    while(sz(sus)) {
        q.eb(sus.back()); sus.pop_back();
        q.eb(jury.back()); jury.pop_back();
    }
    int res = use_machine(q) / 2;
    if(flip) return res;
    return n - res;
}

int count_mushrooms(int n) {
    vector<int> v0(1, 0);
    vector<int> v1;
    int ptr = 1;
    while(ptr < n && max(sz(v0), sz(v1)) < SQ) {
        if(use_machine({0, ptr})) v1.eb(ptr);
        else v0.eb(ptr);
        ptr++;
    }
    int ans = sz(v0);
    if(ptr == n) return ans;
    int flip = 0;
    if(sz(v0) < sz(v1)) {
        v0.swap(v1);
        flip = 1;
    }
    while(ptr < n) {
        int r = min(n - 1, ptr + SQ - 2);
        vector<int> sus;
        For(i, ptr, r) {
            sus.eb(i);
        }
        ptr = r + 1;
        ans += alter(v0, sus, flip);
    }
    return ans;
    // std::vector<int> m;
    // for (int i = 0; i < n; i++)
    // 	m.push_back(i);
    // int c1 = use_machine(m);
    // m = {0, 1};
    // int c2 = use_machine(m);
    // return c1+c2;
}

/*

3
0 1 1

4
0 1 0 0

*/

• Subtask 1: 56.6416 / 100