Submission #984572

#	Time	Username	Problem	Language	Result	Execution time	Memory
984572		SzymonKrzywda	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	64 ms	20948 KiB

shoes

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

const int base = 2<<18;
int tree[base*2+7];

void edit(int n){
    n+=base;
    while (n>0){
        tree[n] += 1;
        n/=2;
    }
}

int query(int a,int b){
    a+=base-1;
    b+=base+1;
    int wynik=0;
    while (a/2 != b/2){
        if (a%2==0) wynik += tree[a+1];
        if (b%2==1) wynik += tree[b-1];
        a/=2;
        b/=2;
    }
    return wynik;
}


long unsigned int count_swaps(vector<int>S){
    long long wynik = 0,len=S.size(),idx_1=0,akt_liczba=0,idx_2=0,idx_3=0;
    pair< vector<int>,int> idx[200007];
    int base_2 = 100001;
    for (int i=0; i<S.size(); i++){
        idx[S[i]+base_2].first.push_back(i);
    }
    
    vector<pair<int,int>> stos(0);
    bool uzyte[200007];
    //Zerujemy 
    for (int i=0; i<200007; i++) uzyte[i] = false;
    
    for (int i=0; i<S.size(); i++){
        //cout << i << " " << uzyte[i] << endl;
        if (!uzyte[i]){
            idx_1 = i;
            idx_2 = idx[(-S[i])+base_2].first[idx[(-S[i])+base_2].second];
            idx[(-S[i])+base_2].second += 1;
            idx[S[i]+base_2].second +=1;
            uzyte[idx_1] = true;
            uzyte[idx_2] = true;
            if (S[idx_2] < S[idx_1]) swap(idx_1,idx_2);
            stos.push_back({idx_1,idx_2});
        }
    }
    //cout << stos.size() << endl; 
    for (int i=0; i<stos.size(); i++){
        //cout << stos[i].first << " " << stos[i].second << endl;
    
        idx_2=stos[i].first;
        wynik += idx_2-(i*2)+query(idx_2+1,len);
        edit(idx_2);
        //cout << wynik << endl;
        
        
        idx_3 = stos[i].second;
        wynik += idx_3-((i*2)+1)+query(idx_3+1,len);
        edit(idx_3);
        //cout << wynik << endl << endl;
    }
    for (int j=0; j<base*2+7; j++){
        tree[j] = 0;
    }

    return wynik;
}

Compilation message (stderr)

shoes.cpp: In function 'long unsigned int count_swaps(std::vector<int>)':
shoes.cpp:34:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |     for (int i=0; i<S.size(); i++){
      |                   ~^~~~~~~~~
shoes.cpp:43:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |     for (int i=0; i<S.size(); i++){
      |                   ~^~~~~~~~~
shoes.cpp:57:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |     for (int i=0; i<stos.size(); i++){
      |                   ~^~~~~~~~~~~~
shoes.cpp:31:46: warning: unused variable 'akt_liczba' [-Wunused-variable]
   31 |     long long wynik = 0,len=S.size(),idx_1=0,akt_liczba=0,idx_2=0,idx_3=0;
      |                                              ^~~~~~~~~~

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