package chap02;
import static org.junit.Assert.*;
import java.util.Arrays;
import java.util.Random;
import org.junit.Test;
/***
* 在归并排序中对小数组采用插入排序
*
* @author xiaojintao
*
*/
public class ques2_1 {
/**
* 归并排序算法
*
* @param a
* @return
*/
static void mergeSortWithInsertSort(int[] a, int start, int end, int k) {
if (start < end - k) {
if (start < end - 1) {
insertSort(a, start, end);
System.out.println("diaoyongle");
}
int mid = (start + end) / 2;
mergeSortWithInsertSort(a, start, mid, k);
mergeSortWithInsertSort(a, mid, end, k);
merge(a, start, mid, end);
}
}
/**
* 归并排序中将两个已经排序的序列合并
*
* @param a
* @param b
* @return
*/
protected static void merge(int[] n, int start, int mid, int end) {
int[] l = Arrays.copyOfRange(n, start, mid);
int[] r = Arrays.copyOfRange(n, mid, end);
int i = 0;
int j = 0;// j<mid-start
int k = 0;// k<end-mid
while (i < end - start) {
if (j < mid - start & k < end - mid) {
if (l[j] < r[k]) {
n[i + start] = l[j];
j++;
} else {
n[i + start] = r[k];
k++;
}
} else if (k < end - mid) {
n[i + start] = r[k];
k++;
} else if (j < mid - start) {
n[i + start] = l[j];
j++;
}
i++;
}
// System.out.println(Arrays.toString(n));
}
/**
* 插入排序算法,对序列中从start到end(不包含end)之间的序列插入排序 start<end
*
* @param n
* @return
*/
static void insertSort(int[] n, int start, int end) {
for (int j = start + 1; j < end; j++) {
int k = n[j];
int i = j - 1;
while (n[i] > k) {
n[i + 1] = n[i];
i--;
if (i == start - 1)
break;
}
n[i + 1] = k;
}
}
}