feat: commit solution 66

Author: lxlxw

_sidebar.md

@@ -18,11 +18,11 @@
   - [27.移除元素 ✅](solution/1-99/0027.remove-element/)
   - [28.实现 strStr() ✅](solution/1-99/0028.implement-strstr/)
   - [35.搜索插入位置 ✅](solution/1-99/0035.search-insert-position/)
+  - [66.加一 ✅](solution/1-99/0066.plus-one/)
   - [88.合并两个有序数组](solution/1-99/0088.merge-sorted-array/)
   - [125.验证回文串 ✅](solution/100-199/0125.valid-palindrome/)
 
 
 
-
 
 

index-tags.md

@@ -28,6 +28,7 @@
 |  [27](https://leetcode-cn.com/problems/remove-element)  |  [移除元素](/solution/1-99/0027.remove-element/)  |  `数组`,`双指针`  |  <font color=green>简单</font>  |✅ |
 |  [35](https://leetcode-cn.com/problems/search-insert-position)  |  [搜索插入位置](/solution/1-99/0035.search-insert-position/)  |  `数组`,`二分查找`  |  <font color=green>简单</font>  |✅ |
 |  [88](https://leetcode-cn.com/problems/merge-sorted-array)  |  [合并两个有序数组](/solution/1-99/0088.merge-sorted-array/)  |  `数组`,`双指针`  |  <font color=green>简单</font>  |✅ |
+|  [66](https://leetcode-cn.com/problems/plus-one)  |  [加一](/solution/1-99/0066.plus-one/)  |  `数组`  |  <font color=green>简单</font>  |✅ |
 
 #### **哈希表**
 

index-type.md

@@ -21,7 +21,7 @@
 |  [38](https://leetcode-cn.com/problems/count-and-say)  |  [外观数列](/solution/1-99/0038.count-and-say/)  |  `字符串`  |  <font color=green>简单</font>  |
 |  [53](https://leetcode-cn.com/problems/maximum-subarray)  |  [最大子序和](/solution/1-99/0053.maximum-subarray/)  |  `数组`,`分治算法`,`动态规划`  |  <font color=green>简单</font>  |
 |  [58](https://leetcode-cn.com/problems/length-of-last-word)  |  [最后一个单词的长度](/solution/1-99/0058.length-of-last-word/)  |  `字符串`  |  <font color=green>简单</font>  |
-|  [66](https://leetcode-cn.com/problems/plus-one)  |  [加一](/solution/1-99/0066.plus-one/)  |  `数组`  |  <font color=green>简单</font>  |
+|  [66](https://leetcode-cn.com/problems/plus-one)  |  [加一](/solution/1-99/0066.plus-one/)  |  `数组`  |  <font color=green>简单</font>  |✅ |
 |  [67](https://leetcode-cn.com/problems/add-binary)  |  [二进制求和](/solution/1-99/0067.add-binary/)  |  `数学`,`字符串`  |  <font color=green>简单</font>  |
 |  [69](https://leetcode-cn.com/problems/sqrtx)  |  [x 的平方根](/solution/1-99/0069.sqrt%28x%29/)  |  `数学`,`二分查找`  |  <font color=green>简单</font>  |
 |  [70](https://leetcode-cn.com/problems/climbing-stairs)  |  [爬楼梯](/solution/1-99/0070.climbing-stairs/)  |  `动态规划`  |  <font color=green>简单</font>  |

solution/1-99/0066.plus-one/README.md

@@ -0,0 +1,56 @@
+# [66.加一](https://leetcode-cn.com/problems/plus-one/)
+
+
+### 题目描述
+
+<div class="notranslate"><p>给定一个由<strong>整数</strong>组成的<strong>非空</strong>数组所表示的非负整数，在该数的基础上加一。</p>
+
+<p>最高位数字存放在数组的首位， 数组中每个元素只存储<strong>单个</strong>数字。</p>
+
+<p>你可以假设除了整数 0 之外，这个整数不会以零开头。</p>
+
+<p><strong>示例&nbsp;1:</strong></p>
+
+<pre><strong>输入:</strong> [1,2,3]
+<strong>输出:</strong> [1,2,4]
+<strong>解释:</strong> 输入数组表示数字 123。
+</pre>
+
+<p><strong>示例&nbsp;2:</strong></p>
+
+<pre><strong>输入:</strong> [4,3,2,1]
+<strong>输出:</strong> [4,3,2,2]
+<strong>解释:</strong> 输入数组表示数字 4321。
+</pre>
+</div>
+
+### 解题思路
+
+1. 末位无进位，则末位加一即可，因为末位无进位，前面也不可能产生进位，比如 123 => 124
+2. 末位有进位，在中间位置进位停止，则需要找到进位的典型标志，即为当前位 %10后为 0，则前一位加 1，直到不为 0 为止，比如 499 => 500
+3. 末位有进位，并且一直进位到最前方导致结果多出一位，对于这种情况，需要在第 2 种情况遍历结束的基础上，进行单独处理，比如 999 => 1000
+
+### 代码实现
+
+<!-- tabs:start -->
+
+#### **Golang**
+```go
+func plusOne(digits []int) []int {
+	n := len(digits)
+	for i := n - 1; i >= 0; i-- {
+		if digits[i] < 9 {
+			digits[i] += 1
+			return digits
+		} else {
+			digits[i] = 0
+		}
+	}
+	ret := make([]int, n+1)
+	ret[0] = 1
+	return ret
+}
+```
+
+
+<!-- tabs:end -->

solution/1-99/0066.plus-one/solution.go

@@ -0,0 +1,25 @@
+package leetcode
+
+/*
+ * @lc app=leetcode.cn id=66 lang=golang
+ *
+ * [66] 加一
+ */
+
+// @lc code=start
+func plusOne(digits []int) []int {
+	n := len(digits)
+	for i := n - 1; i >= 0; i-- {
+		if digits[i] < 9 {
+			digits[i] += 1
+			return digits
+		} else {
+			digits[i] = 0
+		}
+	}
+	ret := make([]int, n+1)
+	ret[0] = 1
+	return ret
+}
+
+// @lc code=end

solution/1-99/0066.plus-one/solution_test.go

@@ -0,0 +1,27 @@
+package leetcode
+
+import (
+	"testing"
+)
+
+func TestPlusOne(t *testing.T) {
+	var nums []int
+	var ret []int
+
+	nums = []int{1, 2, 3}
+	ret = []int{1, 2, 4}
+	plus := plusOne(nums)
+	for k, v := range ret {
+		if plus[k] != v {
+			t.Fatalf("case fails: %v\n", plus)
+		}
+	}
+	nums = []int{9, 9, 9}
+	ret = []int{1, 0, 0, 0}
+	plus = plusOne(nums)
+	for k, v := range ret {
+		if plus[k] != v {
+			t.Fatalf("case fails: %v\n", plus)
+		}
+	}
+}