Submission #1243001

#	Time	Username	Problem	Language	Result	Execution time	Memory
1243001		rayan_bd	Arranging Shoes (IOI19_shoes)	C++20	100 / 100	255 ms	52272 KiB

shoes

#include <bits/stdc++.h>
#include "shoes.h"

using namespace std;

const int mxN = 2e5 + 100;

int seg[mxN * 4], lazy[mxN * 4];
unordered_map<int, set<int>> neg, pos;

void build(int node, int start, int end){
	if(start == end){
		seg[node] = start;
		return;
	}
	int mid = start + (end - start) / 2;
	build(node * 2 + 1, start, mid);
	build(node * 2 + 2, mid + 1, end);
}


void push(int node, int start, int end){
	if(start == end){
		seg[node] += lazy[node];
		lazy[node] = 0;
		return;
	}
	seg[node] += lazy[node];
	lazy[node * 2 + 1] += lazy[node];
	lazy[node * 2 + 2] += lazy[node];
	lazy[node] = 0; 
}

int query(int node, int start, int end, int idx){
	push(node, start, end);
	if(start == end) return seg[node];
	int mid = start + (end - start) / 2;
	if(idx <= mid) return query(node * 2 + 1, start, mid, idx);
	return query(node * 2 + 2, mid + 1, end, idx);
}

void upd(int node, int start, int end, int l, int r){
	push(node, start, end);
	if(l > r) return;
	if(start > r || end < l) return;
	if(start >= l && end <= r){
		lazy[node] = 1;
		push(node, start, end);
		return;
	}
	int mid = start + (end - start) / 2;
	upd(node * 2 + 1, start, mid, l, r);
	upd(node * 2 + 2, mid + 1, end, l, r);
	seg[node] = seg[node * 2 + 1] + seg[node * 2 + 2];
}


long long count_swaps(std::vector<int> s) {

	int n = (int) s.size();
	long long ans = 0;


	build(0, 0, n - 1);

	for(int i = 0; i < n; ++i){
		if(s[i] < 0) neg[s[i]].insert(i);
		else pos[s[i]].insert(i);
	}

	for(int i = 0; i < n; ++i){
		auto lbn = neg[s[i]].lower_bound(i);
		auto lbp = pos[s[i]].lower_bound(i);
		if(*lbn != i && *lbp != i) continue;
		if(s[i] > 0){
			int tp = *neg[-s[i]].begin();
			int curr = query(0, 0, n - 1, tp) - query(0, 0, n - 1, i);
			ans += curr;
			upd(0, 0, n - 1, i, tp - 1);	
			neg[-s[i]].erase(tp);
			pos[s[i]].erase(pos[s[i]].begin());
		}else{	
			int tp = *pos[-s[i]].begin();
			int curr = query(0, 0, n - 1, tp) - query(0, 0, n - 1, i) - 1;
			ans += curr;
			upd(0, 0, n - 1, i + 1, tp - 1);	
			pos[-s[i]].erase(tp);	
			neg[s[i]].erase(neg[s[i]].begin());
		}
	}

	return ans;
}	
/*
int main(){
	freopen("input.in", "r", stdin);
	freopen("output.out", "w", stdout);
	
	//cout << count_swaps({1, 1, 1, -1, -1, -1}) << endl;

	cout << count_swaps({-2, 2, 2, -2, -2, 2}) << endl;

	return 0;
}*/

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