forked from Hithomelabs/Princeton1
51 lines
1.5 KiB
Java
51 lines
1.5 KiB
Java
package com.hithomelabs.princeton1.module7;
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import com.hithomelabs.princeton1.module5.AbstractCustomSorts;
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public class Quick<E> extends AbstractCustomSorts<E> {
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@Override
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public void sort(E[] arr) {
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randomShuffle(arr);
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partition(arr, 0, arr.length-1);
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}
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private void randomShuffle(E[] arr){
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int array_len = arr.length;
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for(int i=0; i< array_len; i++){
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int random_index = (int)(Math.random()*array_len);
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exch(arr, i, random_index);
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}
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}
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private void partition(E[] arr, int low, int high){
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if(low >= high)
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return;
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int mid = sort(arr, low, high);
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partition(arr, low, mid-1);
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partition(arr, mid + 1, high);
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}
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private int sort(E[] arr, int low, int high){
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int i = low+1;
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int j = high;
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while (true){
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// Find the i index greater than 1st element
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while (i<=high && !less((Comparable<E>) arr[low], arr[i]))
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i++;
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// Find the j index less than 1st element
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while (less((Comparable<E>) arr[low], arr[j]) && j > low)
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j--;
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// Break if indexes are crossed
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if(j < i)
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break;
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// Swap index values of i & j
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if(less((Comparable<E>) arr[j], arr[i]))
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exch(arr, i, j);
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}
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// Swap 1st element to it's correct position
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exch(arr, low, j);
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return j;
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}
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}
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