Submission #591424

#	Time	Username	Problem	Language	Result	Execution time	Memory
591424		DAleksa	Arranging Shoes (IOI19_shoes)	C++17	50 / 100	61 ms	20276 KiB

shoes

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

using namespace std;

const int N = 1e5 + 10;

int st[4 * N];

void update(int index, int l, int r, int pos) {
    if(l > r || pos < l || r < pos) return;
    if(l == r) {
        st[index]++;
        return;
    }
    if(l <= pos && pos <= r) st[index]++;
    int mid = (l + r) / 2;
    update(2 * index + 1, l, mid, pos);
    update(2 * index + 2, mid + 1, r, pos);
    st[index] = st[2 * index + 1] + st[2 * index + 2];
}

int get(int index, int l, int r, int L, int R) {
    if(l > r || R < l || r < L) return 0;
    if(L <= l && r <= R) return st[index];
    int mid = (l + r) / 2;
    return get(2 * index + 1, l, mid, L, R) + get(2 * index + 2, mid + 1, r, L, R);
}

long long count_swaps(vector<int> a) {
    int n = a.size();
    long long res = 0;
    vector<int> right[n / 2 + 1];
    for(int i = 0; i < n; i++) if(a[i] > 0) right[a[i]].push_back(i);
    vector<int> ll(n), rr(n);
    vector<int> cnt(n / 2 + 1, 0);
    for(int i = 0; i < n; i++) {
        if(a[i] < 0) {
            if(i < right[-a[i]][cnt[-a[i]]]) {
                ll[i] = i;
                rr[i] = right[-a[i]][cnt[-a[i]]];
                ll[right[-a[i]][cnt[-a[i]]]] = i;
                rr[right[-a[i]][cnt[-a[i]]]] = right[-a[i]][cnt[-a[i]]];
                cnt[-a[i]]++;
            } else {
                res++;
                swap(a[i], a[right[-a[i]][cnt[-a[i]]]]);
                ll[right[a[i]][cnt[a[i]]]] = right[a[i]][cnt[a[i]]];
                rr[right[a[i]][cnt[a[i]]]] = i;
                ll[i] = right[a[i]][cnt[a[i]]];
                rr[i] = i;
                cnt[a[i]]++;
            }
        }
    }
    for(int i = 0; i < n; i++) {
        if(rr[i] == i) {
            res += get(0, 0, n - 1, ll[i], rr[i]);
            update(0, 0, n - 1, ll[i]);
            update(0, 0, n - 1, rr[i]);
        }
    }
    return res;
}

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