Commit d918589

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Add binary search code

1 parent 9d62828 commit d918589Copy full SHA for d918589

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2 files changed

+26

-18

lines changed

src/test/java
- algorithm/basicMath
  - BasicCombination.java
- search
  - BinarySearchTest.java

2 files changed

+26

-18

lines changed

`‎src/test/java/algorithm/basicMath/BasicCombination.java‎`

Lines changed: 7 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,7 @@`
	`1`	`+package algorithm.basicMath;`
	`2`	`+`
	`3`	`+/**`
	`4`	`+ * Created by Jbee on 2017. 6. 5..`
	`5`	`+ */`
	`6`	`+public class BasicCombination {`
	`7`	`+}`

`‎src/test/java/search/BinarySearchTest.java‎`

Lines changed: 19 additions & 18 deletions

Original file line number	Diff line number	Diff line change
`@@ -13,36 +13,37 @@ public class BinarySearchTest {`
`13`	`13`	`*/`
`14`	`14`	`@Test`
`15`	`15`	`public void test() {`
`16`		`- int[] arr = new int[7];`
`17`		`- arr[0] = 52;`
`18`		`- arr[1] = 31;`
`19`		`- arr[2] = 24;`
`20`		`- arr[3] = 45;`
`21`		`- arr[4] = 13;`
`22`		`- arr[5] = 11;`
`23`		`- arr[6] = 28;`
`24`		`- assertThat(searchByRec(arr, 24), is(2));`
`25`		`- assertThat(search(arr, 24), is(2));`
	`16`	`+ int[] arr1 = {11,22,33,44,55,66,77,88};`
	`17`	`+ int[] arr2 = {11,22,33,44,55,66,77};`
	`18`	`+ int[] arr3 = {1};`
	`19`	`+ int[] arr4 = {};`
	`20`	`+ assertThat(search(arr1, 33), is(2));`
	`21`	`+ assertThat(search(arr2, 22), is(1));`
	`22`	`+ assertThat(search(arr3, 1), is(0));`
	`23`	`+ assertThat(search(arr4, 1), is(-1));`
	`24`	`+`
	`25`	`+ assertThat(searchByRec(arr1, 33), is(2));`
	`26`	`+ assertThat(searchByRec(arr2, 22), is(1));`
	`27`	`+ assertThat(searchByRec(arr3, 1), is(0));`
	`28`	`+ assertThat(searchByRec(arr4, 1), is(-1));`
`26`	`29`	`}`
`27`	`30`
`28`	`31`	`// while version`
`29`	`32`	`private int search(int[] arr, int target) {`
`30`	`33`	`if (arr == null) return -1;`
`31`	`34`	`int left = 0;`
`32`	`35`	`int right = arr.length - 1;`
`33`		`-`
	`36`	`+intmid;`
`34`	`37`	`while (left <= right) {`
`35`		`- intmid = left + (right - left) / 2;`
	`38`	`+ mid = left + (right - left) / 2;`
`36`	`39`	`if (arr[mid] == target) {`
`37`	`40`	`return mid;`
`38`	`41`	`}`
`39`	`42`
`40`	`43`	`if (arr[mid] < target) {`
`41`		`- left = mid;`
`42`		`- right -= 1;`
	`44`	`+ left = mid + 1;`
`43`	`45`	`} else {`
`44`		`- right = mid;`
`45`		`- left += 1;`
	`46`	`+ right = mid - 1;`
`46`	`47`	`}`
`47`	`48`	`}`
`48`	`49`	`return -1;`
`@@ -61,9 +62,9 @@ private int searchRec(int[] arr, int left, int right, int target) {`
`61`	`62`	`if (arr[mid] == target) {`
`62`	`63`	`return mid;`
`63`	`64`	`} else if (arr[mid] < target) {`
`64`		`- return searchRec(arr, mid, right - 1, target);`
	`65`	`+ return searchRec(arr, mid + 1, right, target);`
`65`	`66`	`} else {`
`66`		`- return searchRec(arr, left + 1, mid, target);`
	`67`	`+ return searchRec(arr, left, mid - 1, target);`
`67`	`68`	`}`
`68`	`69`	`}`
`69`	`70`	`}`

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Commit d918589

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2 files changed

2 files changed

`‎src/test/java/algorithm/basicMath/BasicCombination.java‎`

`‎src/test/java/search/BinarySearchTest.java‎`

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