Submission #1140166

#	Time	Username	Problem	Language	Result	Execution time	Memory
1140166		grizo	Arranging Shoes (IOI19_shoes)	C++20	100 / 100	194 ms	273652 KiB

shoes

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

using namespace std;
using ll = long long;
#define debug(v)                                                                 \
    cerr << "Line(" << __LINE__ << ") -> " << #v << " = " ; 
#define dbx(x) debug(x); cerr << x << "\n";
#define dbg(x) debug(x); cerr << "{ "; for(auto &e : x) cerr << e << ", "; cerr << "} \n";
#define log(x) (31^__builtin_clz(x))

const int N = 1e6+10, MOD = 1e9+7;

template<typename T> struct BIT
{
    int size = 0;
    vector<T> tree;
    BIT(int n): size(n), tree(n){}
    // 1-indexed pos (0-index just add ++pos)
    void add(int pos, ll val){
        for(++pos ; pos <= size ; pos += (pos & (-pos))) tree[pos - 1] += val;
    }
    T get(int pos){
        T res = 0;
        for(++pos ; pos ; pos -= (pos & (-pos))) res += tree[pos - 1];
        return res;
    }
    T query(int l, int r){
        if(r < l) return 0;
        return get(r) - get(l - 1);
    }
};

ll count_swaps(vector<int> S){

    int n = S.size();
    vector<int> a = S;

    BIT<int> bit(n+1);
    queue<int> l[n+1], r[n+1];

    for(int i = 0 ; i < n ; i ++){
        if(a[i] < 0)l[-a[i]].push(i);
        else r[a[i]].push(i);
    }

    ll ans = 0;
    for(int i = 0 ; i < n ; i ++){
        if(a[i] == 0)continue;

        if(a[i] < 0)
        {
            int j = r[-a[i]].front();

            r[-a[i]].pop();
            l[-a[i]].pop();
            a[j] = 0;

            ans += bit.query(i, j) + j - i - 1;
            bit.add(j, -1);
        }
        else
        {
            int j = l[a[i]].front();

            l[a[i]].pop();
            r[a[i]].pop();
            a[j] = 0;

            ans += bit.query(i, j) + j - i;
            bit.add(j, -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