Submission #1066122

#	Time	Username	Problem	Language	Result	Execution time	Memory
1066122		Ahmed57	Counting Mushrooms (IOI20_mushrooms)	C++17	25.80 / 100	16 ms	1072 KiB

mushrooms

#include "bits/stdc++.h"
using namespace std;
#include "mushrooms.h"
int count_mushrooms(int n){
    int B = 350;
    vector<int> BS;
    int cnt = 0;
    vector<int> pending;
    for(int i = 0;i<n;i+=B){
        vector<int> v;
        if(i!=0)v.push_back(0);
        for(int j = i;j<min(n,i+B);j++)v.push_back(j);
        if(use_machine(v)==0){
            cnt+=(min(i+B,n)-i);
            continue;
        }
        int l = max(1,i) , r =min(n-1,i+B-1) , ans = -1;
        while(l<=r){
            vector<int> v;
            int mid = (l+r)/2;
            if(i!=0)v.push_back(0);
            for(int j = i;j<=mid;j++){
                v.push_back(j);
            }
            if(use_machine(v)!=0){
                ans = mid;
                r = mid-1;
            }else l = mid+1;
        } 
        BS.push_back(ans);
        for(int j = ans+1;j<min(n,i+B);j++){
            pending.push_back(j);
        }
        cnt+=ans-i;
    }
    int sz = BS.size();
    int sz2 = pending.size();
    for(int i = 0;i<pending.size();i+=sz){
        int xd = i;
        vector<int> lol;
        for(int j = i;j<min(sz2,i+sz);j++){
            lol.push_back(BS[j-i]);
            lol.push_back(pending[j]);
        }
        int ans = use_machine(lol);
        if(ans%2){
            cnt++;
            ans--;
        }
        ans/=2;
        cnt+=ans;
    }
    return cnt;
}

Compilation message (stderr)

mushrooms.cpp: In function 'int count_mushrooms(int)':
mushrooms.cpp:38:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |     for(int i = 0;i<pending.size();i+=sz){
      |                   ~^~~~~~~~~~~~~~~
mushrooms.cpp:39:13: warning: unused variable 'xd' [-Wunused-variable]
   39 |         int xd = i;
      |             ^~

• Subtask 1: 25.7991 / 100