Submission #257697

#	Time	Username	Problem	Language	Result	Execution time	Memory
257697		Hehehe	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	623 ms	34284 KiB

shoes

#include<bits/stdc++.h> //:3
using namespace std;
typedef long long ll;
#define all(a) (a).begin(), (a).end()
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
#define pi pair<int, int>
#define sz(x) (int)((x).size())

const int dx[] = {0, 1, 0, -1};
const int dy[] = {1, 0, -1, 0};

const int N = 1e6 + 11;

map<int, set<int>>M;

int t[N];

void update(int v, int l, int r, int pos, int val){
    if(l == r){
        t[v] = val;
        return;
    }

    int mid = (l + r) >> 1;
    if(pos <= mid)update(2*v, l, mid, pos, val);else update(2*v + 1, mid + 1, r, pos, val);

    t[v] = t[2*v] + t[2*v + 1];
}

ll q(int v, int tl, int tr, int l, int r){

    if(tl > r || tr < l)return 0;

    if(l <= tl && tr <= r){
        return t[v];
    }

    int mid = (tl + tr) >> 1;
    return q(2*v, tl, mid, l, r) + q(2*v + 1, mid + 1, tr, l, r);
}

ll count_swaps(vector<int> A){

    int n = sz(A);

    vector<int>a;
    a.push_back(0);

    for(auto it : A)a.push_back(it);

    for(int i = 1; i <= n; i++){
        update(1, 1, n, i, 1);
        M[a[i]].insert(i);
    }

    ll ans = 0;

    for(int i = 1; i <= n; i++){

        if(q(1, 1, n, i, i) == 0)continue;

        if(a[i] > 0)ans++;

        int x = *M[-a[i]].begin();

        ans += (i + 1 <= x - 1 ? q(1, 1, n, i + 1, x - 1) : 0);

        M[a[i]].erase(*M[a[i]].begin());
        M[-a[i]].erase(*M[-a[i]].begin());

        update(1, 1, n, i, 0);
        update(1, 1, n, x, 0);
    }

    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