add worst_best_time_complexity.go

codes/go/chapter_computational_complexity/time_complexity/worst_best_time_complexity.go

@@ -0,0 +1,45 @@
+// File: worst_best_time_complexity.go
+// Created Time: 2022-12-13
+// Author: msk397 (machangxinq@gmail.com)
+
+package time_complexity
+
+import (
+	"fmt"
+	"math/rand"
+)
+
+/* 生成一个数组，元素为 { 1, 2, ..., n }，顺序被打乱 */
+func randomNumbers(n int) []int {
+	nums := make([]int, n)
+	// 生成数组 nums = { 1, 2, 3, ..., n }
+	for i := 0; i < n; i++ {
+		nums[i] = i + 1
+	}
+	// 随机打乱数组元素
+	rand.Shuffle(len(nums), func(i, j int) {
+		nums[i], nums[j] = nums[j], nums[i]
+	})
+	return nums
+}
+
+/* 查找数组 nums 中数字 1 所在索引 */
+func findOne(nums []int) int {
+	for i := 0; i < len(nums); i++ {
+		if nums[i] == 1 {
+			return i
+		}
+	}
+	return -1
+}
+
+/* Driver Code */
+func main() {
+	for i := 0; i < 10; i++ {
+		n := 100
+		nums := randomNumbers(n)
+		index := findOne(nums)
+		fmt.Println("\n数组 [ 1, 2, ..., n ] 被打乱后 =", nums)
+		fmt.Println("数字 1 的索引为", index)
+	}
+}