java算法专题-归并排序

归并的思想就是分治.时间复杂度..忘记了

大概实现了下..还真挺费劲的...

很受打击啊...还有什么好的排序算法..大家给推荐下我试着弄弄

没怎么写注释..以此作为我的备用.

这几天的思考中我终于发现..理解和会用和精通是两个概念..

学海无涯.人生苦短啊

public class Test1 {
	public static void main(String[] args) {
		int[] arr1 = { 4,23,234,3,41,311,3,5 ,56,5,46};
		int[] arr2 = { 4,23,234,3,41,311,3,5 ,56,5,46};
		Test1 test1 = new Test1();
		test1.splitAndMerger(arr1, 0, arr1.length-1);
		test1.printArray(arr1);
		test1.printArray(arr2) ;
		Arrays.sort(arr2) ;
		test1.printArray(arr2) ;
	}

	public void splitAndMerger(int[] ints, int begin, int end) {
		int mid = (begin + end) / 2;
		if (end > begin) {
			splitAndMerger(ints, begin, mid);
			splitAndMerger(ints, mid + 1, end);
			merger(ints, begin, mid, end);
		}
	}

	public void merger(int[] ints, int begin, int mid, int end) {
		int temp1 = 0;
		int temp2 = 0;
		int[] arr1 = Arrays.copyOfRange(ints, begin, mid+1);
		int[] arr2 = Arrays.copyOfRange(ints, mid+1, end+1);

		for (int i = begin; i <= end; i++) {
			if (temp1 == arr1.length  && temp2 == arr2.length) {
				break;
			}
			if (temp1 == arr1.length) {
				ints[i] = arr2[temp2];
				temp2++;
				continue;
			}
			if (temp2 == arr2.length) {
				ints[i] = arr1[temp1];
				temp1++;
				continue;
			}
			if (arr1[temp1] > arr2[temp2]) {
				ints[i] = arr2[temp2];
				temp2++;
			} else {
				ints[i] = arr1[temp1];
				temp1++;
			}
		}
	}

	public void printArray(int[] array) {
		this.printArray(array, 0, array.length-1);
	}

	public void printArray(int[] array, int begin, int end) {
		for (int i = begin; i <= end; i++) {
			System.out.print(array[i] + "	");
		}
		System.out.println();
	}
}