189 accepted

329ms, fastest is 123ms

Author: aQua

Algorithms/0189.rotate-array/README.md

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+# [189. Rotate Array](https://leetcode.com/problems/rotate-array/)
+
+## 题目
+
+Rotate an array of n elements to the right by k steps.
+For example, with n = 7 and k = 3, the array `[1,2,3,4,5,6,7]` is rotated to `[5,6,7,1,2,3,4]`. 
+
+Note:
+Try to come up as many solutions as you can, there are at least 3 different ways to solve this problem.
+
+
+[show hint]
+Hint:
+Could you do it in-place with O(1) extra space?
+
+
+Related problem: [Reverse Words in a String II](https://leetcode.com/problems/reverse-words-in-a-string-ii/)
+
+## 解题思路
+
+
+见程序注释

Algorithms/0189.rotate-array/rotate-array.go

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+package Problem0189
+
+func rotate(nums []int, k int) {
+	for i := 0; i < k; i++ {
+		temp := nums[len(nums)-1]
+		for j := len(nums) - 1; j > 0; j-- {
+			nums[j] = nums[j-1]
+		}
+		nums[0] = temp
+	}
+}

Algorithms/0189.rotate-array/rotate-array_test.go

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+package Problem0189
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type question struct {
+	para
+	ans
+}
+
+// para 是参数
+type para struct {
+	nums []int
+	k    int
+}
+
+// ans 是答案
+type ans struct {
+	one []int
+}
+
+func Test_Problem0189(t *testing.T) {
+	ast := assert.New(t)
+
+	qs := []question{
+
+		question{
+			para{
+				[]int{1, 2, 3, 4, 5, 6, 7}, 3,
+			},
+			ans{
+				[]int{5, 6, 7, 1, 2, 3, 4},
+			},
+		},
+
+		// 如需多个测试，可以复制上方元素。
+	}
+
+	for _, q := range qs {
+		a, p := q.ans, q.para
+		fmt.Printf("~~%v~~\n", p)
+		rotate(p.nums, p.k)
+		ast.Equal(a.one, p.nums, "输入:%v", p)
+	}
+}