Submission #783796

#	Time	Username	Problem	Language	Result	Execution time	Memory
783796		GrindMachine	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	103 ms	139696 KiB

shoes

// Om Namah Shivaya

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*



*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

#include "shoes.h"

template<typename T>
struct fenwick {
    int siz;
    vector<T> tree;

    fenwick(int n) {
        siz = n;
        tree = vector<T>(n + 1);
    }

    int lsb(int x) {
        return x & -x;
    }

    void build(vector<T> &a, int n) {
        for (int i = 1; i <= n; ++i) {
            int par = i + lsb(i);
            tree[i] += a[i];

            if (par <= siz) {
                tree[par] += tree[i];
            }
        }
    }

    void pupd(int i, T v) {
    	i++;

        while (i <= siz) {
            tree[i] += v;
            i += lsb(i);
        }
    }

    T sum(int i) {
    	i++;

        T res = 0;

        while (i) {
            res += tree[i];
            i -= lsb(i);
        }

        return res;
    }

    T query(int l, int r) {
        if (l > r) return 0;
        T res = sum(r) - sum(l - 1);
        return res;
    }
};

long long count_swaps(vector<int> a) {
	int n = sz(a);
	vector<int> b(n,-1);
	deque<int> here[n];
	int ptr = 0;

	rep(i,n){
		int x = abs(a[i]);
		bool ok = false;

		if(!here[x].empty()){
			if(a[i] < 0){
				if(a[here[x].front()] > 0){
					b[ptr] = i;
					b[ptr+1] = here[x].front();
					ptr += 2;
					here[x].pop_front();
					ok = true;
				}
			}
			else{
				if(a[here[x].front()] < 0){
					b[ptr] = here[x].front();
					b[ptr+1] = i;
					ptr += 2;
					here[x].pop_front();
					ok = true;
				}
			}
		}

		if(!ok){
			here[x].pb(i);
		}
	}

	rep(i,n) assert(b[i] != -1);

	fenwick<int> fenw(n);
	ll ans = 0;

	rep(i,n){
		ans += fenw.query(b[i]+1,n-1);
		fenw.pupd(b[i],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