Submission #938918

#	Time	Username	Problem	Language	Result	Execution time	Memory
938918		Ariadna	Arranging Shoes (IOI19_shoes)	C++14	10 / 100	0 ms	432 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
#define ll long long
 
using namespace std;
 
struct Segtree {
    int n;
    vector<int> st;
 
    Segtree(int N) {
        n = N;
        st = vector<int>(4*n, 0);
    }
 
    void change(int p, int l, int r, int i) {
        if (l == r) st[p] = 1-st[p];
        else {
            int m = (l+r)/2;
            if (i <= m) change(2*p, l, m, i);
            else change(2*p+1, m+1, r, i);
            st[p] = st[2*p] + st[2*p+1];
        }
    }
 
    int sum(int p, int l, int r, int i, int j) {
        if (i > j) return 0;
        if (l == i && r == j) return st[p];
        int m = (l+r)/2;
        return sum(2*p, l, m, i, min(m, j)) + sum(2*p+1, m+1, r, max(m+1, i), j);
    }
 
    void change(int i) { change(1, 0, n-1, i); }
    int sum(int i, int j) { return sum(1, 0, n-1, i, j); }
};
 
ll count_swaps(vector<int> s) {
    int n = (int)s.size();
 
    Segtree St(n);
    ll ans = 0;
    map<int, int> pos;
    for (int i = 0; i < n; ++i) {
        if (s[i] < 0) {
            if (pos.find(-s[i]) != pos.end()) {
                s[i] *= -1;
                ans += i - pos[s[i]];
                St.change(pos[s[i]]);
                ans -= St.sum(pos[s[i]], i);
                pos.erase(s[i]);
            } else {
                pos[s[i]] = i;
                St.change(i);
            }
        } else {
            if (pos.find(-s[i]) != pos.end()) {
                s[i] *= -1;
                ans += i - pos[s[i]] - 1;
                St.change(pos[s[i]]);
                ans -= St.sum(pos[s[i]], i);
                pos.erase(s[i]);
            } else {
                pos[s[i]] = i;
                St.change(i);
            }
        }
    }
 
    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