Submission #836353

#	Time	Username	Problem	Language	Result	Execution time	Memory
836353		maomao90	Counting Mushrooms (IOI20_mushrooms)	C++17	80.71 / 100	8 ms	496 KiB

mushrooms

// I can do all things through Christ who strengthens me
// Philippians 4:13

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

#define REP(i, j, k) for (int i = j; i < (k); i++)
#define RREP(i, j, k) for (int i = j; i >= (k); i--)

template <class T>
inline bool mnto(T &a, const T b) {return a > b ? a = b, 1 : 0;}
template <class T>
inline bool mxto(T &a, const T b) {return a < b ? a = b, 1 : 0;}

typedef long long ll;
typedef long double ld;
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
#define ALL(x) x.begin(), x.end()
#define SZ(x) (int) x.size()
#define pb push_back
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;
typedef tuple<int, int, int> iii;
typedef vector<iii> viii;

#ifndef DEBUG
#define cerr if (0) cerr
#endif

const int INF = 1000000005;
const ll LINF = 1000000000000000005;
const int MAXN = 20005;

mt19937 rnd(8);

int n;
int ans;
vi know[2];

int count_mushrooms(int _n) {
    n = _n;
    ans = 1;
    know[0].pb(0);
    vi id(n);
    iota(ALL(id), 0);
    shuffle(1 + ALL(id), rnd);
    int ptr = 1;
    while (ptr < n) {
        int r = use_machine({0, id[ptr]});
        know[r].pb(id[ptr]);
        ans += r == 0;
        ptr++;
        if (SZ(know[r]) >= 2) {
            break;
        }
    }
    while (ptr < n) {
        bool t = SZ(know[1]) > SZ(know[0]);
        int kptr = 0;
        vi x;
        while (ptr < n && kptr < SZ(know[t])) {
            x.pb(know[t][kptr++]);
            x.pb(id[ptr++]);
        }
        int r = use_machine(x);
        int occ = r / 2 + (r % 2);
        if (t) {
            ans += occ;
        } else {
            ans += SZ(x) / 2 - occ;
        }
        know[t ^ (r % 2)].pb(id[ptr - 1]);
    }
    return ans;
}

• Subtask 1: 80.7143 / 100