Learn a bit every day algorithm-merge sort algorithm __ algorithm

Merge Sort Algorithm

definition

Merge sort (merge sort, Taiwan translation: Combined sorting) is an efficient sorting algorithm based on merging operations. This algorithm is a very typical application of the partition method (Divide and Conquer).

Steps

1. Apply the space so that it is the sum of two sorted sequences that are used to store the merged sequence

2. Set two pointers, the initial position is the starting position of two sorted series

3. Compare the elements pointed to by two pointers, select a relatively small element into the merge space, and move the pointer to the next position

4. Repeat step 3 until a pointer reaches the end of the sequence

5. Copy all remaining elements of another sequence directly to the end of the merge sequence

Complexity of Time

O (NLOGN)

Code

Package com.sprd.test.algorithm; /** * Copyright TJ spreadtrum TEST_AF All right Reserved * * @author: Hui.qian Created on November 27, 2014 morning 9:09:13 D Escription: */public class MergeSort {public int[] sort (int[] A, int[] b) {int[] merge = new Int[a.length + B.leng
		TH];
		int indexa = 0;
		int INDEXB = 0;
		int i = 0; while (Indexa < a.length && Indexb < b.length) {if (A[indexa] <= B[indexb]) {merge[i++] = A[inde
			Xa++];
			} else {merge[i++] = b[indexb++];
			}} if (indexa = = A.length) {for (int j = Indexb; Indexb < b.length; indexb++) {merge[i++] = B[indexb];
			}} else {for (int j = indexa; indexa < a.length; indexa++) {merge[i++] = B[indexa];
	}} return merge;
		} public static void Main (string[] args) {int[] sorta = {1, 3, 5, 7, 9};
		Int[] SORTB = {2, 4, 6, 8, 10};
		MergeSort sorter = new MergeSort ();
		Long start = System.currenttimemillis ();
		int[] sorted = Sorter.sort (sorta, SORTB); LOng end = System.currenttimemillis ();
		SYSTEM.OUT.PRINTLN ("Time Consuming:" + (End-start));
		System.out.println ("Before sorting:");
		print (sorta);
		Print (SORTB);
		System.out.println ("After sorting:");
	print (sorted);  public static void print (int[] datas) {for (int i = 0; i < datas.length; i++) {System.out.print (Datas[i] + "
		");
	} System.out.println ("");
 }
}

Output

Time: 0
before sequencing: 
1 3 5 7 9 
2 4 6 8 
after sorting: