Submission #312361

#	Time	Username	Problem	Language	Result	Execution time	Memory
312361		nonthaphat	Counting Mushrooms (IOI20_mushrooms)	C++14	99.56 / 100	12 ms	512 KiB

mushrooms

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

typedef long long ll;
typedef long double ld;
typedef double db;

typedef pair<int, int> pii;
typedef pair<int, ll> pil;
typedef pair<ll, int> pli;
typedef pair<ll, ll> pll;
typedef pair<pii, int> piipi;
typedef pair<int, pii> pipii;
typedef pair<pii, pii> piipii;
typedef pair<ll, pii> plpii;
typedef pair<db, db> pdd;
typedef pair<ld, ld> pldd;

typedef vector<int> vi;
typedef vector<pii> vii;

#define FOR(i, a, b) for(int i=(a);i<(b);++i)
#define FOR2(i, a, b) for(int i=(a);i<=(b);++i)
#define ROF(i, a, b) for(int i=(b)-1;i>=(a);--i)
#define ROF2(i, a, b) for(int i=(b);i>=(a);--i)
#define GO(i, x) for(auto &i : x)

#define mp make_pair
#define fi first
#define se second
#define sz(x) (int)x.size()
#define all(x) (x).begin(), (x).end()
#define eb emplace_back
#define pf push_front
#define pb push_back
#define lb lower_bound
#define up upper_bound

template<typename T> inline bool min2(T &a, const T &b) { return b < a ? a = b, 1 : 0; }
template<typename T> inline bool max2(T &a, const T &b) { return a < b ? a = b, 1 : 0; }

const int mod = 1e9 + 7;
// const int mod = 998244353;
const int P1 = 999983, P2 = 999979;
const ld PI = acos((ld)-1);
const int dir[4][2] = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};
const ll INF = 1e18;
const int N = 1e6;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int sq = 185;
int use_machine(vector<int> x);
int count_mushrooms(int n){
    int ansA = 0, ansB = 0;
    vector<int> A, B;
    A.eb(0);
    int k = 1;
    if(n <= sq+10){
        while(sz(A) + sz(B) < n){
            vector<int> x;
            x.eb(0);
            x.eb(k);
            int res = use_machine(x);
            if(res == 0) A.eb(k);
            else B.eb(k);
            k++;
        }
        ansA = sz(A);
        ansB = sz(B);
    }
    else{
        while(sz(A) < 2 && sz(B) < 2 && sz(A) + sz(B) < sq){
            vector<int> x;
            x.eb(0);
            x.eb(k);
            int res = use_machine(x);
            if(res == 0) A.eb(k);
            else B.eb(k);
            k++;
        }
        while(((sz(A) < 3 || sz(B) < 2) && (sz(B) < 3 || sz(A) < 2)) && sz(A) + sz(B) < sq){
            vector<int> x;
            bool sw = 0;
            if(sz(A) < sz(B)){
                sw = 1;
                swap(A, B);
            }
            x.eb(k);
            x.eb(A[0]);
            x.eb(k+1);
            x.eb(A[1]);
            int res = use_machine(x);
            if(res%2 == 0) A.eb(k);
            else B.eb(k);
            if(res/2 == 0) A.eb(k+1);
            else B.eb(k+1);
            k += 2;
            if(sw) swap(A, B);
        }
        while(sz(A) + sz(B) < sq){
            vector<int> x;
            bool sw = 0;
            if(sz(A) < sz(B)){
                sw = 1;
                swap(A, B);
            }
            x.eb(k);
            x.eb(A[0]);
            x.eb(k+1);
            x.eb(A[1]);
            x.eb(k+2);
            x.eb(A[2]);
            int res = use_machine(x);
            if(res%2 == 0) A.eb(k);
            else B.eb(k);
            if(res/2 == 0) A.eb(k+1), A.eb(k+2), k += 3;
            else if(res/2 == 2) B.eb(k+1), B.eb(k+2), k += 3;
            else{
                x.clear();
                x.eb(B[0]);
                x.eb(k+1);
                x.eb(B[1]);
                x.eb(A[0]);
                x.eb(k+2);
                x.eb(A[1]);
                x.eb(k+3);
                x.eb(A[2]);
                x.eb(k+4);

                int res = use_machine(x);
                if(res%2 == 1) A.eb(k+4);
                else B.eb(k+4);

                if(res >= 5){
                    A.eb(k+1);
                    B.eb(k+2);
                    if(res < 7) A.eb(k+3);
                    else B.eb(k+3);
                }
                else{
                    A.eb(k+2);
                    B.eb(k+1);
                    if(res < 3) A.eb(k+3);
                    else B.eb(k+3);
                }
                k += 5;
            }
            if(sw) swap(A, B);
        }

        ansA = sz(A);
        ansB = sz(B);
        while(ansA + ansB < n){
            vector<int> x;
            bool sw = 0;
            if(sz(A) < sz(B)){
                sw = 1;
                swap(A, B);
                swap(ansA, ansB);
            }

            int le = min(sz(A), n-k);
            for(int i=0;i<le;i++){
                x.eb(k+i);
                x.eb(A[i]);
            }

            int res = use_machine(x);
            if(res%2 == 0) A.eb(k), ansA++;
            else B.eb(k), ansB++;
            ansA += (le-1) - res/2;
            ansB += res/2;
            k += le;

            if(sw){
                swap(A, B);
                swap(ansA, ansB);
            }
        }
    }
    return ansA;
}

• Subtask 1: 99.5595 / 100