제출 #1054723

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1054723		RecursiveCo	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	67 ms	17468 KiB

shoes

#include <bits/stdc++.h>

using namespace std;

vector<int> tree;

void upd(int v, int i, int l, int r) {
    if (l == r) tree[v]++;
    else {
        int middle = (l + r) / 2;
        if (i <= middle) upd(2 * v, i, l, middle);
        else upd(2 * v + 1, i, middle + 1, r);
        tree[v] = tree[2 * v] + tree[2 * v + 1];
    }
}

int query(int v, int ql, int qr, int l, int r) {
    if (ql <= l && r <= qr) return tree[v];
    if (r < ql || qr < l) return 0;
    int middle = (l + r) / 2;
    int left = query(2 * v, ql, qr, l, middle);
    int right = query(2 * v + 1, ql, qr, middle + 1, r);
    return left + right;
}

long long count_swaps(vector<int> nums) {
    int n = nums.size() / 2;
    vector<vector<int>> left(n + 1);
    vector<vector<int>> right(n + 1);
    for (int i = 0; i < 2 * n; i++) {
        if (nums[i] < 0) left[-nums[i]].push_back(i);
        else right[nums[i]].push_back(i);
    }
    vector<pair<int, int>> segs;
    long long ans = 0;
    for (int i = 0; i <= n; i++) {
        int s = left[i].size();
        for (int j = 0; j < s; j++) {
            int l = left[i][j];
            int r = right[i][j];
            if (l > r) {
                ans++;
                swap(l, r);
            }
            segs.push_back({l, r});
        }
    }
    sort(segs.begin(), segs.end());
    vector<int> arr(2 * n);
    for (int i = 0; i < n; i++) {
        arr[segs[i].first] = i;
        arr[segs[i].second] = i;
    }
    tree.resize(4 * n, 0);
    for (int i = 0; i < 2 * n; i++) {
        int val = arr[i];
        int add = val == n - 1? 0: query(1, val + 1, n - 1, 0, n - 1);
        ans += (long long) add;
        upd(1, val, 0, n - 1);
    }
    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