Submission #723984

#	Time	Username	Problem	Language	Result	Execution time	Memory
723984		sandry24	Arranging Shoes (IOI19_shoes)	C++17	10 / 100	1 ms	704 KiB

shoes

#include <bits/stdc++.h>
using namespace std;

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> pi;
#define pb push_back
#define mp make_pair
#define f first
#define s second

const int sz = 100005;
vector<int> BIT(sz);

void add(int x, int delta){
    for(; x <= sz; x += x & -x)
        BIT[x] += delta;
}

ll sum(int x){
    ll res = 0;
    for(; x > 0; x -= x & -x)
        res += BIT[x];
    return res;
}

int count_swaps(vi s){
    map<int, vi> m;
    int n = s.size();
    vector<bool> marked(n);
    for(int i = 0; i < n; i++)
        m[s[i]].pb(i);
    for(auto i : m)
        reverse(i.s.begin(), i.s.end());
    ll ans = 0;
    for(int i = 0; i < n; i++){
        if(marked[i])
            continue;
        int need = -s[i];
        int ind = m[need].back();
        m[need].pop_back();
        m[s[i]].pop_back();
        marked[i] = marked[ind] = 1;
        //cout << s[i] << ' ' << i << ' ' << ind << ' ' << sum(ind) << '\n';
        ans += (ind - i - 1) - (sum(ind+1) - sum(i+1));
        if(s[i] > 0)
            ans++;
        add(ind+1, 1);
        //cout << ans << '\n';
    }
    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