Submission #601958

#	Time	Username	Problem	Language	Result	Execution time	Memory
601958		FatihSolak	Counting Mushrooms (IOI20_mushrooms)	C++17	0 / 100	2 ms	208 KiB

mushrooms

#include "mushrooms.h"
#include <bits/stdc++.h>
#define N 20000
#define X 187
using namespace std;

int count_mushrooms(int n){
	int mini = 0;
	int val = 1e9;
	for(int i = 1;i<N;i++){
		if(i-1 + (N - i + (i+1)/2 -1)/( (i+1)/2) < val){
			val = i-1 + (N - i + (i+1)/2 -1)/( (i+1)/2);
			mini = i;
		}
	}
	//cout << mini << " " << val << endl;
	if(n <= 227){
		int ret = 1;
		for(int i = 1;i<n;i++){
			ret += !(use_machine({0,i}));
		}
		return ret;
	}
	vector<int> a,b;
	a.push_back(0);
	int point  = 1;
	int cur = 0;
	while( (n-point + max(a.size(),b.size()) - 1) / max(a.size(),b.size()) + cur > 300 ){
		int asz = a.size();
		int bsz = b.size();
		if(asz > bsz){
			int len = 0;
			while((1<<(len+1)) <= asz * 2){
				len++;
			}
			vector<int> points;
			vector<int> ask;
			int cnt = 0;
			for(int i = len-1;i>=0;i--){
				for(int j = 0;j<(1<<i);j++){
					ask.push_back(a[cnt++]);
					ask.push_back(point);
				}
				points.push_back(point);
				point++;
			}
			reverse(points.begin(),points.end());
			int mask = use_machine(ask);
			for(int i = 0;i<len;i++){
				if(mask & (1<<i)){
					b.push_back(points[i]);
				}
				else a.push_back(points[i]);
			}
		}
		else{
			int len = 0;
			while((1<<(len+1)) <= bsz * 2){
				len++;
			}
			vector<int> points;
			vector<int> ask;
			int cnt = 0;
			for(int i = len-1;i>=0;i--){
				for(int j = 0;j<(1<<i);j++){
					ask.push_back(b[cnt++]);
					ask.push_back(point);
				}
				points.push_back(point);
				point++;
			}
			reverse(points.begin(),points.end());
			int mask = use_machine(ask);
			for(int i = 0;i<len;i++){
				if(mask & (1<<i)){
					a.push_back(points[i]);
				}
				else b.push_back(points[i]);
			}
		}
		cur++;
	}
	// for(int i = 1;i<=X;i++){
	// 	if(use_machine({0,i})){
	// 		b.push_back(i);
	// 	}
	// 	else a.push_back(i);
	// }
	int ret = 0;
	int asz = a.size();
	int bsz = b.size();
	if(asz > bsz){
		for(int i = X+1;i<n;i+=asz){
			vector<int> nums;
			int cnt = 0;
			for(int j = i;j<min(n,i + asz);j++){
				nums.push_back(a[cnt++]);
				nums.push_back(j);
			}
			int sz = nums.size()/2;
			ret += sz - (use_machine(nums) + 1)/2;
		}
	}
	else{
		for(int i = X+1;i<n;i+=bsz){
			vector<int> nums;
			int cnt = 0;
			for(int j = i;j<min(n,i + bsz);j++){
				nums.push_back(b[cnt++]);
				nums.push_back(j);
			}
			int sz = nums.size()/2;
			ret += (use_machine(nums) + 1)/2;
		}
	}

	return ret + asz;
}

Compilation message (stderr)

mushrooms.cpp: In function 'int count_mushrooms(int)':
mushrooms.cpp:112:8: warning: unused variable 'sz' [-Wunused-variable]
  112 |    int sz = nums.size()/2;
      |        ^~
mushrooms.cpp:8:6: warning: variable 'mini' set but not used [-Wunused-but-set-variable]
    8 |  int mini = 0;
      |      ^~~~

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