Submission #403796

#	Time	Username	Problem	Language	Result	Execution time	Memory
403796		dxz05	Arranging Shoes (IOI19_shoes)	C++14	10 / 100	367 ms	285332 KiB

shoes

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

using namespace std;

typedef long long ll;

const int MAXN = 4e5 + 6e3;

int n;
int f[MAXN];

void add(int x, int y){
    x++;
    while (x < MAXN){
        f[x] += y;
        x += (-x & x);
    }
}

void add(int l, int r, int y){
    if (l > r) return;
    add(l, y);
    add(r + 1, -y);
}

int get(int x){
    x++;
    int sum = 0;
    while (x > 0){
        sum += f[x];
        x -= (-x & x);
    }
    return sum;
}

int get(int l, int r){
    return get(r) - get(l - 1);
}

int code(int val){
    return (val < 0 ? -val : val + 200000);
}

queue<int> q[MAXN];

long long count_swaps(vector<int> a) {
	n = a.size();

    set<pair<int, int>> s;
	for (int i = 0; i < n; i++){
        int x = code(a[i]);
        q[x].push(i);
        s.insert(make_pair(q[x].front(), a[i]));
	}

    ll ans = 0;

    while (!s.empty()) {
        int val = s.begin()->second;

        s.erase(s.begin());

        int x = code(val), y = code(-val);
        s.erase(make_pair(q[y].front(), -val));

        int pos1 = q[x].front(), pos2 = q[y].front();
        pos1 += get(pos1), pos2 += get(pos2);

        if (pos1 > pos2) swap(pos1, pos2);

   //     cout << pos1 << ' ' << pos2 << endl;

        ans += pos2 - pos1 - 1 + (val > 0);

        add(pos1 + 1, pos2 - 1, 1);
        q[x].pop();
        q[y].pop();

        if (!q[x].empty()) s.insert(make_pair(q[x].front(), val));
        if (!q[y].empty()) s.insert(make_pair(q[y].front(), -val));
    }

	return ans;
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 15