插入排序算法

public class InsertSortTest {/*** @param args*/public static void main(String[] args) {int[] a={3,5,9,16,29,47,78,89,94};int key=47;int[] b=insertSort(a,key);for(int i=0;i<b.length;i++){System.out.print(b[i]+" "); }}public static int[] insertSort(int[] unsorted,int key){int len=unsorted.length;int[] sorted=new int[len+1];for(int i=0;i<len;i++){//when key exists in edge of arrayif(key<unsorted[0]){sorted[0]=key;System.arraycopy(unsorted, 0, sorted, 1, len);}if(key>unsorted[len-1]){sorted[sorted.length-1]=key;System.arraycopy(unsorted, 0, sorted, 0, len);}//when key exists in mid of arrayif(key>unsorted[i]){sorted[i]=unsorted[i];}else{sorted[i]=key;System.arraycopy(unsorted, i, sorted, i+1, len-i);break;}}return sorted;} }

單元測試源碼：（使用junit4）

public class InsertSortUnitTest {@Testpublic void testLT() {int[] a={3,5,9,16,29,47,78,89,94};int key=-5;int[] result={-5,3,5,9,16,29,47,78,89,94};int[] b=InsertSortTest.insertSort(a,key);for(int i=0;i<result.length;i++){assertEquals(result[i],b[i]);}}@Testpublic void testGT() {int[] a={3,5,9,16,29,47,78,89,94};int key=205;int[] result={3,5,9,16,29,47,78,89,94,205};int[] b=InsertSortTest.insertSort(a,key);for(int i=0;i<result.length;i++){assertEquals(result[i],b[i]);}}@Testpublic void testMid() {int[] a={3,5,9,16,29,47,78,89,94};int key=50;int[] result={3,5,9,16,29,47,50,78,89,94};int[] b=InsertSortTest.insertSort(a,key);for(int i=0;i<result.length;i++){assertEquals(result[i],b[i]);}}@Testpublic void testEqual(){int[] a={3,5,9,16,29,47,78,89,94};int key=47;int[] result={3,5,9,16,29,47,47,78,89,94};int[] b=InsertSortTest.insertSort(a,key);for(int i=0;i<result.length;i++){assertEquals(result[i],b[i]);}} }

?程序進一步優化：

public class InsertSortTest {/*** @param args*/public static void main(String[] args) {Comparable[] a={3f,5f,9f,16f,29f,47f,78f,89f,94f};Comparable key=47.78f;Comparable[] b=insertSort(a,key);for(int i=0;i<b.length;i++){System.out.print(b[i]+" "); }}public static Comparable[] insertSort(Comparable[] unsorted,Comparable key){int len=unsorted.length;Comparable[] sorted=new Comparable[len+1];for(int i=0;i<len;i++){//when key exists in edge of arrayif(key.compareTo(unsorted[0])<0){sorted[0]=key;System.arraycopy(unsorted, 0, sorted, 1, len);}if(key.compareTo(unsorted[len-1])>0){sorted[sorted.length-1]=key;System.arraycopy(unsorted, 0, sorted, 0, len);}//when key exists in mid of arrayif(key.compareTo(unsorted[i])>0){sorted[i]=unsorted[i];}else{sorted[i]=key;System.arraycopy(unsorted, i, sorted, i+1, len-i);break;}}return sorted;} }

單元測試的就略過了吧。

?

轉載于:https://www.cnblogs.com/davidwang456/p/3474750.html

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