合并排序函数

Posted 2021-02-26

public static void MergeSort(int[] array) {
		if(array.length>1){
			int elementsInA1=array.length/2;
			int elementsInA2=elementsInA1;
			if((array.length%2)==1)
				elementsInA2+=1;
 
			int arr1[]=new int[elementsInA1];
			int arr2[]=new int[elementsInA2];
 
			for(int i=0; i<elementsInA1; i++)
				arr1[i]=array[i];
 
			for(int i=elementsInA1; i<elementsInA1+elementsInA2; i++)
				arr2[i-elementsInA1]=array[i];
 
			MergeSort(arr1);
 
			MergeSort(arr2);
 
 
			int i=0, j=0, k=0;
 
			while(arr1.length!=j && arr2.length!=k){
				if(arr1[j]<=arr2[k]) {
					array[i]=arr1[j];
					j++;
				}else{
					array[i]=arr2[k];
					k++;
				}
				i++;
			}
 
			while(arr1.length!=j){
				array[i]=arr1[j];
				i++;
				j++;
			}
			while(arr2.length!=k){
				array[i]=arr2[k];
				i++;
				k++;
			}
		}
	}