Submission #152335

#	Time	Username	Problem	Language	Result	Execution time	Memory
152335		groeneprof	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	116 ms	14992 KiB

shoes

#include <bits/stdc++.h>
//#define int long long
#define P(x) do {if(debug) cout << x << endl;} while(false)
#define H(x) P(#x << ": " << x)
#define FR(i, a, b) for(int i = (a); i < (b); ++i)
#define F(i, n) FR(i, 0, n)
#define DR(i, a, b) for(int i = (b); i --> (a);)
#define D(i, n) DR(i, 0, n)
#define S(s) (int)(s).size()
#define ALL(x) (x).begin(), (x).end()
#define MI(x, a) (x) = min(x, a)
#define MA(x, a) (x) = max(x, a)
#define V vector
#define pb push_back
#define mp make_pair
using namespace std;
const bool debug = 0;
//const int inf = 1e18;

struct ftree{
	vector<int> tree;
	int n;
	ftree(int _n){
		tree.resize(_n+1, 0);
		n = _n;
	}
	int query(int i){
		int res = 0;
		for(int j = i; j>0; j-=(j&-j)){
			res+=tree[j];
		}
		//res+=ftree[0];µ
		return res;
	}

	void update(int i, int change){
		//int change = v-(query(i+1)+query(i));
		for(int j = i+1; j<tree.size(); j+=(j&-j)){
			tree[j]+=change;
		}
	}
};

long long count_swaps(vector<int> S){
	int n = S.size()/2;
	//cout<<"AAA";
	vector<vector<int> > pos(2*n+5);
	for(int i = 2*n-1; i>=0; i--){
		H(S[i]);
		H(S[i]+n);
		pos[S[i]+n].push_back(i);

	}
	ftree ft(2*n);
	vector<bool> vis(2*n, 0);
	long long cnt = 0;
	//cout<<"blib"<<endl;
	for(int i = 0; i < 2*n; i++){
		if(vis[i]) continue;
		int x = pos[n-S[i]].back();
		pos[n-S[i]].pop_back();
		pos[S[i]+n].pop_back();
		H(i);
		H(x);
		H( x - i - ((S[i]<0)?1:0));
		cnt += x - i - ((S[i]<0)?1:0);
		H(cnt);
		cnt -= ft.query(x) - ft.query(i+1);
		H(cnt);
		ft.update(x, 1);
		vis[x]=true;
	}
	return cnt;
}

Compilation message (stderr)

shoes.cpp: In member function 'void ftree::update(int, int)':
shoes.cpp:38:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j = i+1; j<tree.size(); j+=(j&-j)){
                    ~^~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 15 / 15
• Subtask 5: 20 / 20
• Subtask 6: 15 / 15