42 lines
1.4 KiB
Java
42 lines
1.4 KiB
Java
package com.hithomelabs.princeton1.module6;
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import com.hithomelabs.princeton1.module5.AbstractCustomSorts;
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import java.util.Arrays;
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public class Merge<E> extends AbstractCustomSorts<E> {
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@Override
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public void sort(E[] arr) {
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merge_sort(arr, 0, arr.length-1);
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}
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private void merge_sort(E[] arr, int low_index, int high_index){
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System.out.println(low_index + " " + high_index);
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if(high_index - low_index > 0) {
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int mid_index = low_index + (high_index - low_index)/2;
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merge_sort(arr, low_index, mid_index);
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merge_sort(arr, mid_index + 1, high_index);
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// Copy array
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E[] auxArr = (E[]) new Object[arr.length];
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System.arraycopy(arr, 0, auxArr, 0, arr.length);
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// Sort
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int low_index_ptr = low_index;
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int high_index_ptr = mid_index + 1;
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for(int i=low_index; i<= high_index; i++){
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if(low_index_ptr > mid_index)
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arr[i] = auxArr[high_index_ptr++];
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else if(high_index_ptr > high_index)
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arr[i] = auxArr[low_index_ptr++];
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else if(less((Comparable<E>) auxArr[low_index_ptr], auxArr[high_index_ptr]))
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arr[i] = auxArr[low_index_ptr++];
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else
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arr[i] = auxArr[high_index_ptr++];
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}
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}
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}
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}
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