Submission #1158381

#	Time	Username	Problem	Language	Result	Execution time	Memory
1158381		ackhava	Counting Mushrooms (IOI20_mushrooms)	C++20	75.84 / 100	3 ms	512 KiB

mushrooms

#include "mushrooms.h"
#include <vector>
#include <bits/stdc++.h>
#define REP(v, i, j) for (long long v = i; v != j; v++)
#define FORI(v) for (auto i : v)
#define FORJ(v) for (auto j : v)

#define OUT(v, a) \
    FORI(v)       \
    cout << i << a;
#define OUTS(v, a, b)      \
    cout << v.size() << a; \
    OUT(v, b)
#define in(a, n) \
    REP(i, 0, n) \
    cin >> a[i];

#define SORT(v) sort(begin(v), end(v))
#define REV(v) reverse(begin(v), end(v))
#define MEMSET(m) memset(m, -1, sizeof m)

#define pb push_back
#define fi first
#define se second

#define detachIO                      \
    ios_base::sync_with_stdio(false); \
    cin.tie(0);                       \
    cout.tie(0);
    
using namespace std;

template<typename _Tp, typename _Alloc = std::allocator<_Tp> >
bool operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y) {
    if(__x.size() != __y.size()) return false;
    return std::equal(__x.begin(), __x.end(), __y.begin());
}


typedef pair<long long, long long> pii;
typedef pair<pii, long long> piii;
typedef pair<pii, pii> piiii;

const long long MOD = 1e9+7;

struct modint {
    long long val;

    modint() = default;
    modint(int _val): val(_val){}
    modint operator+(modint b){ return ((this->val + b.val)%MOD); }
    modint operator-(modint b){ return ((MOD + this->val - b.val)%MOD); }
    modint operator*(modint b){ return ((this->val * b.val)%MOD); }
    modint operator^(int a){
        if(a==0)return 1;
        if(a==1)return *this;
        return (((*this)*(*this))^(a>>1))*((*this)^(a&1)); 
    }
};

modint invert(modint a){
    return a^(MOD-2);
}

modint operator/(modint a, modint b){
    return a*invert(b);
}

struct segment_tree {
    long long n;
    typedef int T;
    vector<T> seg;
    const T e = 2e9;

    T merge(T a, T b){
        if(a==e)return b;
        if(b==e)return a;
        return min(a,b);
    }

    segment_tree(long long _n): n(_n),seg(4*_n+10,e) /** BUG: GCC does not initialize the elements properly this way */ {
        for(auto &i:seg)i=e;
    }

    void update(long long pos, long long l, long long r, long long idx, T val){
        if(r<idx)return;
        if(l>idx)return;
        if(l==r){
            seg[pos]=val;
            return;
        }
        update(pos*2+1,l,(l+r)/2,idx,val);
        update(pos*2+2,((l+r)/2)+1,r,idx,val);
        seg[pos]=merge(seg[pos*2+1],seg[pos*2+2]);
    }

    T query(long long pos, long long l, long long r, long long ql, long long qr){
        if(l > qr)return e;
        if(ql > r)return e;
        if(ql <= l && r <= qr)return seg[pos];
        if(l==r)return e;
        return merge(query(pos*2+1,l,(l+r)/2,ql,qr),query(pos*2+2,((l+r)/2)+1,r,ql,qr));
    }
};

int count_mushrooms(int n) {
	vector<int> a,b;
	queue<int> q;
	REP(i,1,n)q.push(i);
	a.pb(0);
	while((q.size()>=2)&&(a.size()+b.size())<=200){
		auto x=q.front();q.pop();
		auto y=q.front();q.pop();
		if(a.size()>=2){
			int r=use_machine({a[0],x,a[1],y});
			if(r&2)b.pb(x);else a.pb(x);
			if(r&1)b.pb(y);else a.pb(y);
		} else if(b.size()>=2){
			int r=use_machine({b[0],x,b[1],y});
			if(r&2)a.pb(x);else b.pb(x);
			if(r&1)a.pb(y);else b.pb(y);
		} else {
			int r=use_machine({a[0],x});
			if(r)b.pb(x);else a.pb(x);
			r=use_machine({a[0],y});
			if(r)b.pb(y);else a.pb(y);
		}
	}
	int ans=a.size();
	while(q.size()){
		if(a.size()>b.size()){
			vector<int> vec;
			FORI(a){
				if(q.size())vec.pb(q.front()),vec.pb(i),q.pop();
			}
			int x=use_machine(vec);
			ans+=(vec.size()/2)-((x>>1)+(x&1));
		}else{
			vector<int> vec;
			FORI(b){
				if(q.size())vec.pb(q.front()),vec.pb(i),q.pop();
			}
			int x=use_machine(vec);
			ans+=((x>>1)+(x&1));
		}
	}
	
	return ans;
}

• Subtask 1: 75.8389 / 100