Submission #404100

#	Time	Username	Problem	Language	Result	Execution time	Memory
404100		Theo830	Arranging Shoes (IOI19_shoes)	C++17	30 / 100	165 ms	20384 KiB

shoes

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
ll INF = 1e9+7;
ll MOD = 998244353;
typedef pair<ll,ll> ii;
#define iii pair<ll,ii>
#define f(i,a,b) for(ll i = a;i < b;i++)
#define pb push_back
#define vll vector<ll>
#define F first
#define S second
#define all(x) (x).begin(), (x).end()
///I hope I will get uprating and don't make mistakes
///I will never stop programming
///sqrt(-1) Love C++
///Please don't hack me
///@TheofanisOrfanou Theo830
///Think different approaches (bs,dp,greedy,graphs,shortest paths,mst)
///Stay Calm
///Look for special cases
///Beware of overflow and array bounds
///Think the problem backwards
///Training
//#include "shoes.h"
long long count_swaps(std::vector<int> S){
    ll ans = 0;
    ll m = S.size();
    vll exo[m+5];
    f(i,0,m){
        exo[abs(S[i])].pb(S[i]);
    }
    f(i,0,m){
        vll s;
        set<ll>p,pll;
        ll pos = 0;
        for(auto x:exo[i]){
            s.pb(x);
            if(x < 0){
                pll.insert(pos);
            }
            else{
                p.insert(pos);
            }
            pos++;
        }
        ll n = s.size();
        f(i,0,n){
            if(s[i] < 0 && s[i+1] > 0){

            }
            else if(s[i] > 0 && s[i+1] < 0){
                ans++;
                p.erase(i);
                pll.erase(i+1);
                p.insert(i+1);
                pll.insert(i);
            }
            else if(s[i] < 0 && s[i+1] < 0){
                ll f;
                for(auto x:p){
                    f = x;
                    p.erase(f);
                    pll.insert(f);
                    pll.erase(i+1);
                    p.insert(i+1);
                    swap(s[i+1],s[f]);
                    break;
                }
                ans += f - (i+1);
            }
            else{
                ll f;
                for(auto x:pll){
                    f = x;
                    pll.erase(f);
                    p.insert(f);
                    p.erase(i);
                    pll.insert(i);
                    swap(s[i],s[f]);
                    break;
                }
                ans += f - i;
            }
            p.erase(i+1);
            pll.erase(i);
            i++;
        }
    }
    return ans;
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 20
• Subtask 3: 20 / 20
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 15