Submission #528695

#	Time	Username	Problem	Language	Result	Execution time	Memory
528695		happypotato	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	247 ms	141020 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int mxN = 2e5 + 1;
int seg[4 * mxN];
int n;
void update(int tar, int l = 1, int r = n, int idx = 1) {
    if (l == r) {
        seg[idx] ^= 1;
        return;
    }
    int mid = (l + r) >> 1;
    if (tar <= mid) update(tar, l, mid, (idx << 1));
    else update(tar, mid + 1, r, (idx << 1) + 1);
    seg[idx] = seg[(idx << 1)] + seg[(idx << 1) + 1];
    return;
}
int query(int tarl, int tarr, int l = 1, int r = n, int idx = 1) {
    if (tarl > tarr) return 0;
    if (tarl <= l && r <= tarr) return seg[idx];
    else if (tarr < l || r < tarl) return 0;
    int mid = (l + r) >> 1;
    return query(tarl, min(tarr, mid), l, mid, (idx << 1)) + query(max(tarl, mid + 1), tarr, mid + 1, r, (idx << 1) + 1);
}
long long count_swaps(vector<int> s) {
    n = s.size();
    queue<int> q[n + 1];
    int cnt = 1;
    int a[n + 1];
    for (int i = 0; i < n; i++) {
        if (!q[s[i] + n / 2].empty()) {
            a[i] = q[s[i] + n / 2].front();
            q[s[i] + n / 2].pop();
        } else {
            a[i] = (s[i] < 0 ? cnt : cnt + 1);
            q[-s[i] + n / 2].push((s[i] < 0 ? cnt + 1 : cnt));
            cnt += 2;
        }
    }
    // for (int i = 0; i < n; i++) cerr << a[i] << ' ';
    // cerr << endl;
    ll int ans = 0;
    for (int i = 0; i < n; i++) {
        ans += query(a[i] + 1, n);
        update(a[i]);
    }
    return ans;
}

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