Submission #545123

#	Time	Username	Problem	Language	Result	Execution time	Memory
545123		Lobo	Counting Mushrooms (IOI20_mushrooms)	C++17	92.62 / 100	10 ms	456 KiB

mushrooms

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

const long long inf = (long long) 1e18 + 10;
const int inf1 = (int) 1e9 + 10;
// #define int long long
#define dbl long double
#define endl '\n'
#define sc second
#define fr first
#define mp make_pair
#define pb push_back
#define all(x) x.begin(), x.end()

const int maxn = 2e4 + 10;


// int s[maxn];
// int use_machine(vector<int> x) {
//     const int xs = x.size();
    
//     int diffs = 0;
//     for (int i = 1; i < xs; i++)
//         diffs += int(s[x[i]] != s[x[i-1]]);
//     return diffs;
// }

int a[maxn];

int count_mushrooms(int n) {
    int B = 80;

    vector<int> va, vb;
    a[0] = 1;
    va.pb(0);
    for(int i = 1; i < n; i++) {
        if(i == n-1 || n <= 226) {
            vector<int> vqr; vqr.pb(0); vqr.pb(i);
            if(use_machine(vqr) == 0) {
                va.pb(i);
                a[i] = 1;
            }
            else {
                vb.pb(i);
                a[i] = 1;
            }
            continue;
        }

        if(va.size() < 2 && vb.size() < 2) {
            vector<int> vqr; vqr.pb(0); vqr.pb(i);
            if(use_machine(vqr) == 0) {
                a[i] = 1;
                va.pb(i);
            }
            else {
                a[i] = 1;
                vb.pb(i);
            }
        }
        else if(va.size() >= 2) {
            vector<int> vqr;
            vqr.pb(i);
            vqr.pb(va[0]);
            vqr.pb(i+1);
            vqr.pb(va[1]);

            int qr = use_machine(vqr);
            qr = ((int) vqr.size()) -1 - qr;

            a[i] = 1;
            a[i+1] = 1;
            if(qr == 0) {
                vb.pb(i);
                vb.pb(i+1);
            }
            else if(qr == 1) {
                va.pb(i);
                vb.pb(i+1);
            }
            else if(qr == 2) {
                vb.pb(i);
                va.pb(i+1);
            }
            else {
                va.pb(i);
                va.pb(i+1);
            }
            i++;
        }
        else {
            vector<int> vqr;
            vqr.pb(i);
            vqr.pb(vb[0]);
            vqr.pb(i+1);
            vqr.pb(vb[1]);

            int qr = use_machine(vqr);
            qr = ((int) vqr.size()) -1 - qr;

            a[i] = 1;
            a[i+1] = 1;
            if(qr == 0) {
                va.pb(i);
                va.pb(i+1);
            }
            else if(qr == 1) {
                vb.pb(i);
                va.pb(i+1);
            }
            else if(qr == 2) {
                va.pb(i);
                vb.pb(i+1);
            }
            else {
                vb.pb(i);
                vb.pb(i+1);
            }
            i++;
        }

        if(va.size() >= B || vb.size() >= B) break;
    }

    int ans = va.size();

    int i = 1;
    while(i < n) {
        while(i < n && a[i]) i++;
        if(va.size() > vb.size()) {
            int j = 0;
            vector<int> vqr;
            while(j < va.size() && i < n) {
                if(a[i] != 0) {
                    i++;
                    continue;
                }
                vqr.pb(va[j++]);
                vqr.pb(i++);
            }
            if(vqr.size() == 0) continue;
            int qr = use_machine(vqr);
            qr = ((int) vqr.size()) -1 - qr;
            ans+= qr/2;


            if(qr%2 == 1) {
                va.pb(vqr.back());
                ans++;
            }
            else {
                vb.pb(vqr.back());
            }
        }
        else {
            int j = 0;
            vector<int> vqr;
            while(j < vb.size() && i < n) {
                if(a[i] != 0) {
                    i++;
                    continue;
                }
                vqr.pb(vb[j++]);
                vqr.pb(i++);
            }
            if(vqr.size() == 0) continue;
            int qr = use_machine(vqr);
            qr = ((int) vqr.size()) -1 - qr;
            ans+= ((int) vqr.size())/2 - qr/2 - 1;

            if(qr%2 == 1) {
                vb.pb(vqr.back());
            }
            else {
                va.pb(vqr.back());
                ans++;
            }
        }
    }
    return ans;


}


// int32_t main() {
//     ios::sync_with_stdio(false); cin.tie(0);

//     freopen("in.in", "r", stdin);
//     // freopen("out.out", "w", stdout);
    
//     int n;
//     cin >> n;
//     for(int i = 0; i < n; i++) {
//         int x; cin >> x;
//         s[i] = x;
//     }

//     cout << count_mushrooms(n) << endl;

// }

Compilation message (stderr)

mushrooms.cpp: In function 'int count_mushrooms(int)':
mushrooms.cpp:123:22: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  123 |         if(va.size() >= B || vb.size() >= B) break;
      |            ~~~~~~~~~~^~~~
mushrooms.cpp:123:40: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  123 |         if(va.size() >= B || vb.size() >= B) break;
      |                              ~~~~~~~~~~^~~~
mushrooms.cpp:134:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  134 |             while(j < va.size() && i < n) {
      |                   ~~^~~~~~~~~~~
mushrooms.cpp:159:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  159 |             while(j < vb.size() && i < n) {
      |                   ~~^~~~~~~~~~~

• Subtask 1: 92.623 / 100