2017.4.20

Juntaran · Juntaran · commit 624ef90a67b1 · 2017-04-20T14:45:09.000+08:00
Some search algorithm
diff --git a/Algorithm/Search/Binary_Search/binary_search.go b/Algorithm/Search/Binary_Search/binary_search.go
@@ -0,0 +1,23 @@
+/**
+  * Author: Juntaran
+  * Email:  Jacinthmail@gmail.com
+  * Date:   2017/4/20 14:15
+  */
+
+package Binary_Search
+
+// 二分查找首先要数组有序
+func Binary_Search(nums []int, key int) int {
+	left, right := 0, len(nums)-1
+	for left <= right {
+		middle := (right - left) >> 1 + left
+		if key < nums[middle] {
+			right = middle - 1
+		} else if key > nums[middle] {
+			left = middle + 1
+		} else {
+			return middle
+		}
+	}
+	return -1
+}
diff --git a/Algorithm/Search/Fibonacci_Search/fibonacci_search.go b/Algorithm/Search/Fibonacci_Search/fibonacci_search.go
@@ -0,0 +1,52 @@
+/**
+  * Author: Juntaran
+  * Email:  Jacinthmail@gmail.com
+  * Date:   2017/4/20 14:33
+  */
+
+package Fibonacci_Search
+
+// 斐波那契查找
+func Fibonacci_Search(nums []int, key int) int {
+	// 斐波那契数列
+	var Fibonacci [1000]int
+	Fibonacci[0] = 0
+	Fibonacci[1] = 1
+	for i := 2; i < 1000; i++ {
+		Fibonacci[i] = Fibonacci[i-1] + Fibonacci[i-2]
+	}
+	left, right := 0, len(nums)-1
+	k := 0
+	// 计算n位于斐波那契数列的位置
+	for len(nums) > Fibonacci[k] - 1 {
+		k ++
+	}
+	// 扩展nums到Fibonacci[k]-1的长度
+	var temp = new([Fibonacci[k]-1]int)
+	for i := 0; i < len(nums); i++ {
+		temp[i] = nums[i]
+	}
+	// 填充剩余部分
+	for i := len(nums); i < Fibonacci[k]-1; i++ {
+		temp[i] = nums[len(nums) - 1]
+	}
+	for left <= right {
+		middle := left + Fibonacci[k-1] - 1
+		if key < temp[middle] {
+			right = middle - 1
+			// 斐波那契数列下标-1
+			k = k - 1
+		} else if key > temp[middle] {
+			left = middle + 1
+			// 斐波那契数列下标-2
+			k = k - 2
+		} else {
+			if middle < len(nums) {
+				return middle
+			} else {
+				return len(nums) - 1
+			}
+		}
+	}
+	return -1
+}
diff --git a/Algorithm/Search/Insert_Search/insert_search.go b/Algorithm/Search/Insert_Search/insert_search.go
@@ -0,0 +1,24 @@
+/**
+  * Author: Juntaran
+  * Email:  Jacinthmail@gmail.com
+  * Date:   2017/4/20 14:29
+  */
+
+package Insert_Search
+
+// 插值查找
+func Insert_Search(nums []int, key int) int {
+	left, right := 0, len(nums)
+	for left <= right {
+		// 差值查找只在middle的取值和二分不同
+		middle := left + (right-left) * (key-nums[left]) / (nums[right] - nums[left])
+		if key < nums[middle] {
+			right = middle - 1
+		} else if key > nums[middle] {
+			left = middle + 1
+		} else {
+			return middle
+		}
+	}
+	return -1
+}
diff --git a/Algorithm/Search/Sequence_Search/sequence_search.go b/Algorithm/Search/Sequence_Search/sequence_search.go
@@ -0,0 +1,16 @@
+/**
+  * Author: Juntaran
+  * Email:  Jacinthmail@gmail.com
+  * Date:   2017/4/20 14:22
+  */
+
+package Sequence_Search
+
+func Sequence_Search(nums []int, key int) int {
+	for i := 0; i < len(nums); i++ {
+		if nums[i] == key {
+			return i
+		}
+	}
+	return -1
+}
diff --git a/Algorithm/Search/Sequence_Search/sequence_search_2.go b/Algorithm/Search/Sequence_Search/sequence_search_2.go
@@ -0,0 +1,23 @@
+/**
+  * Author: Juntaran
+  * Email:  Jacinthmail@gmail.com
+  * Date:   2017/4/20 14:24
+  */
+
+package Sequence_Search
+
+// 哨兵顺序查找
+func Sequence_Search_2(nums []int, key int) int {
+	if nums[0] == key {
+		return 0
+	}
+	i := len(nums)
+	for nums[i] != key && i != 0 {
+		i --
+	}
+	if i == 0 {
+		return -1
+	} else {
+		return i
+	}
+}
