Submission #466349

#	Time	Username	Problem	Language	Result	Execution time	Memory
466349		NintsiChkhaidze	Arranging Shoes (IOI19_shoes)	C++14	10 / 100	1079 ms	25848 KiB

shoes

#include "shoes.h"
#include <iostream>
#include <vector>
#include <algorithm>
#include <math.h>
#define pb push_back
#define ll long long
using namespace std;

const int N = 100005;
vector <int> lf[N],rg[N];
bool f[N];
ll fen[N];
pair<int,pair<int,int> > d[N];

void upd(int ind,int val){
    while(ind <= N){
        fen[ind] += val;
        ind += (ind&(-ind));
    }
}
ll get(int ind){
    ll s=0;
    while(ind){
        s += fen[ind];
        ind -= (ind&(-ind));
    }
    return s;
}

ll count_swaps(vector <int> a) {
    for (int i = 0; i < a.size(); i++){
        if (a[i] < 0) lf[-a[i]].pb(i);
        else rg[a[i]].pb(i);
    }

    ll cnt = 0;
    for (int i = 0; i < a.size(); i++){
        if (f[i]) continue;

        if (a[i] < 0){
            int ind = rg[-a[i]][0];
            f[ind] = 1;

            rg[-a[i]].erase(rg[-a[i]].begin());
            d[++cnt] = {abs(ind - i),{i,ind}};

            lf[-a[i]].erase(lf[-a[i]].begin());
        }
        else{
            int ind = lf[a[i]][0];
            f[ind] = 1;

            lf[a[i]].erase(lf[a[i]].begin());
            d[++cnt] = {abs(ind - i),{ind,i}};

            rg[a[i]].erase(rg[a[i]].begin());
        }
    }

    sort(d + 1,d + cnt + 1);

    ll ans=0;
    for (int i = 1; i <= cnt; i++){
        int l = d[i].second.first,r = d[i].second.second;
        if (l > r) swap(l,r);
        ans += r - l - 1 + get(r + 1) - get(l);
        if (a[l] > 0 && a[r] < 0) ans++;

        upd(l + 1, -1);
        upd(r + 1, -1);
    }

    return ans;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:32:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |     for (int i = 0; i < a.size(); i++){
      |                     ~~^~~~~~~~~~
shoes.cpp:38:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |     for (int i = 0; i < a.size(); i++){
      |                     ~~^~~~~~~~~~

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