Submission #897580

#	Time	Username	Problem	Language	Result	Execution time	Memory
897580		Essa2006	Counting Mushrooms (IOI20_mushrooms)	C++14	0 / 100	1 ms	344 KiB

mushrooms

#include<bits/stdc++.h>
using namespace std;
#define ll long long 
#define endl '\n'
#define FF first
#define SS second
#define all(a) a.begin(), a.end()
#define mod (ll)(1000000007)

#include "mushrooms.h"
//vector<int> B;
//
//int use_machine(vector<int> X){
//    int res = 0;
//    for (int i = 1; i < X.size(); i++) {
//        if (B[X[i] - 1] != B[X[i - 1] - 1]) {
//            res++;
//        }
//    }   
//    return res;
//}

int count_mushrooms(int n) {
    
	vector<int> A(n);
    for (int i = 0; i < n; i++) {
        A[i] = i + 1;
    }
    random_shuffle(A.begin() + 1, A.end());
    
    int ans = 1;
    
    int fir, sec;
    
    int cur = use_machine({1, A[1]});
    
    if (n == 2)
        return ans + !cur;
    
    int cur2 = use_machine({1, A[2]});
    
    if (!cur || !cur2) {
        ans += 1 + (!cur & !cur2);
        
        fir = 1;
        if (!cur) {
            sec = A[1];
        }
        else {
            sec = A[2];
        }
        
        for (int i = 3; i < n; i += 3) {
            if (n - i == 1) {
                int diff = use_machine({fir, A[i]});
                ans += 1 - diff;
            }
            else if (n - i == 2) {
                int diff = use_machine({A[i], fir, A[i + 1]});
                ans += 2 - diff;
            }
            else {
                int diff = use_machine({A[i], fir, A[i + 1], sec, A[i + 2]});
                if (diff <= 1) {
                    ans += 3 - diff;
                }
                else if(diff >= 3) {
                    ans += 4 - diff;
                }
                else {
                    int diff2 = use_machine({fir, A[i + 1]});
                    if (diff2) {
                        ans += 2;
                    }
                    else {
                        ans++;
                    }
                }
            }
        }
        
        
    }
    else {
        fir = A[1], sec = A[2];
        
        for (int i = 3; i < n; i += 3) {
            if (n - i == 1) {
                int diff = use_machine({fir, A[i]});
                ans += diff;
            }
            else if (n - i == 2) {
                int diff = use_machine({A[i], fir, A[i + 1]});
                ans += diff;
            }
            else {
                int diff = use_machine({A[i], fir, A[i + 1], sec, A[i + 2]});
                if (diff <= 1) {
                    ans += diff;
                }
                else if(diff >= 3) {
                    ans += diff - 1;
                }
                else {
                    int diff2 = use_machine({fir, A[i + 1]});
                    if (diff2) {
                        ans ++;
                    }
                    else {
                        ans += 2;
                    }
                }
            }
        }
    }
    
    return ans;
}

//int main() {
//    int n;
//    cin >> n;
//    
//    B.resize(n);
//    
//    for (int i = 0; i < n; i++) {
//        cin >> B[i];
//    }
//    
//    cout << count_mushrooms(n);
//}

• Subtask 1: 0 / 100