Cod sursa(job #2900176)

Utilizator StanCatalinStanCatalin StanCatalin Data 10 mai 2022 14:55:45
Problema Sortare prin comparare Scor 60
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.67 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <stdlib.h>
#include <time.h>

using namespace std;

ifstream in("algsort.in");
ofstream out("algsort.out");

const int dim = 500005;

int vec[dim];
int n;

void MergeSort(int *vec, int n) {
    if (n <= 1) return;
    int *vec1, *vec2;
    vec1 = vec;
    int a_n = n/2;
    vec2 = vec + n/2;
    int b_n = n - n/2;
    MergeSort(vec1, a_n);
    MergeSort(vec2, b_n);
    int i = 0;
    int j = 0;
    vector<int> newvec;
    while (i < a_n && j < b_n) {
        if (vec1[i] <= vec2[j]) {
            newvec.push_back(vec1[i++]);
        } else {
            newvec.push_back(vec2[j++]);
        }
    }
    while (i < a_n) {
        newvec.push_back(vec1[i++]);
    }
    while (j < b_n) {
        newvec.push_back(vec2[j++]);
    }
    int cnt = 0;
    for (auto &y:newvec) {
        vec[cnt++] = y;
    }
}

int Partition(int *vec, int st, int dr) {
    int index = st + rand() % (dr - st + 1);
    swap(vec[dr], vec[index]);
    int pivot = dr;
    int k = st;
    for (int i = st; i <= dr; i++) {
        if (vec[i] < vec[pivot]) {
            swap(vec[i], vec[k]);
            k++;
        }
    }
    swap(vec[k], vec[pivot]);
    return k;
}

void QuickSort(int *vec, int st, int dr){
    if (st < dr) {
        int index = Partition(vec, st, dr);
        QuickSort(vec, st, index-1);
        QuickSort(vec, index+1, dr);
    }
}

int main()
{
    srand(time(NULL));
    in >> n;
    for (int i=0; i<n; i++) {
        in >> vec[i];
    }
    QuickSort(vec, 0, n-1);
    for (int i=0; i<n; i++) {

        out << vec[i] << " ";
    }
    return 0;
}