Merge pull request halfrost#38 from halfrost/add_hugo

Add hugo

Author: halfrost

leetcode/0009.Palindrome-Number/9. Palindrome Number.go

@@ -0,0 +1,20 @@
+package leetcode
+
+import "strconv"
+
+func isPalindrome(x int) bool {
+	if x < 0 {
+		return false
+	}
+	if x < 10 {
+		return true
+	}
+	s := strconv.Itoa(x)
+	length := len(s)
+	for i := 0; i <= length/2; i++ {
+		if s[i] != s[length-1-i] {
+			return false
+		}
+	}
+	return true
+}

leetcode/0009.Palindrome-Number/9. Palindrome Number_test.go

@@ -0,0 +1,72 @@
+package leetcode
+
+import (
+	"fmt"
+	"testing"
+)
+
+type question9 struct {
+	para9
+	ans9
+}
+
+// para 是参数
+// one 代表第一个参数
+type para9 struct {
+	one int
+}
+
+// ans 是答案
+// one 代表第一个答案
+type ans9 struct {
+	one bool
+}
+
+func Test_Problem9(t *testing.T) {
+
+	qs := []question9{
+
+		question9{
+			para9{121},
+			ans9{true},
+		},
+
+		question9{
+			para9{-121},
+			ans9{false},
+		},
+
+		question9{
+			para9{10},
+			ans9{false},
+		},
+
+		question9{
+			para9{321},
+			ans9{false},
+		},
+
+		question9{
+			para9{-123},
+			ans9{false},
+		},
+
+		question9{
+			para9{120},
+			ans9{false},
+		},
+
+		question9{
+			para9{1534236469},
+			ans9{false},
+		},
+	}
+
+	fmt.Printf("------------------------Leetcode Problem 9------------------------\n")
+
+	for _, q := range qs {
+		_, p := q.ans9, q.para9
+		fmt.Printf("【input】:%v    【output】:%v\n", p.one, isPalindrome(p.one))
+	}
+	fmt.Printf("\n\n\n")
+}

leetcode/0009.Palindrome-Number/README.md

@@ -0,0 +1,69 @@
+# [9. Palindrome Number](https://leetcode.com/problems/palindrome-number/)
+
+
+## 题目
+
+Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward.
+
+**Example 1**:
+
+```
+Input: 121
+Output: true
+```
+
+**Example 2**:
+
+```
+Input: -121
+Output: false
+Explanation: From left to right, it reads -121. From right to left, it becomes 121-. Therefore it is not a palindrome.
+```
+
+**Example 3**:
+
+```
+Input: 10
+Output: false
+Explanation: Reads 01 from right to left. Therefore it is not a palindrome.
+```
+
+**Follow up**:
+
+Coud you solve it without converting the integer to a string?
+
+## 题目大意
+
+判断一个整数是否是回文数。回文数是指正序（从左向右）和倒序（从右向左）读都是一样的整数。
+
+## 解题思路
+
+- 判断一个整数是不是回文数。
+- 简单题。注意会有负数的情况，负数，个位数，10 都不是回文数。其他的整数再按照回文的规则判断。
+
+## 代码
+
+```go
+
+package leetcode
+
+import "strconv"
+
+func isPalindrome(x int) bool {
+	if x < 0 {
+		return false
+	}
+	if x < 10 {
+		return true
+	}
+	s := strconv.Itoa(x)
+	length := len(s)
+	for i := 0; i <= length/2; i++ {
+		if s[i] != s[length-1-i] {
+			return false
+		}
+	}
+	return true
+}
+
+```

leetcode/0013.Roman-to-Integer/13. Roman to Integer.go

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+package leetcode
+
+var roman = map[string]int{
+	"I": 1,
+	"V": 5,
+	"X": 10,
+	"L": 50,
+	"C": 100,
+	"D": 500,
+	"M": 1000,
+}
+
+func romanToInt(s string) int {
+	if s == "" {
+		return 0
+	}
+	num, lastint, total := 0, 0, 0
+	for i := 0; i < len(s); i++ {
+		char := s[len(s)-(i+1) : len(s)-i]
+		num = roman[char]
+		if num < lastint {
+			total = total - num
+		} else {
+			total = total + num
+		}
+		lastint = num
+	}
+	return total
+}

leetcode/0013.Roman-to-Integer/13. Roman to Integer_test.go

@@ -0,0 +1,67 @@
+package leetcode
+
+import (
+	"fmt"
+	"testing"
+)
+
+type question13 struct {
+	para13
+	ans13
+}
+
+// para 是参数
+// one 代表第一个参数
+type para13 struct {
+	one string
+}
+
+// ans 是答案
+// one 代表第一个答案
+type ans13 struct {
+	one int
+}
+
+func Test_Problem13(t *testing.T) {
+
+	qs := []question13{
+
+		question13{
+			para13{"III"},
+			ans13{3},
+		},
+
+		question13{
+			para13{"IV"},
+			ans13{4},
+		},
+
+		question13{
+			para13{"IX"},
+			ans13{9},
+		},
+
+		question13{
+			para13{"LVIII"},
+			ans13{58},
+		},
+
+		question13{
+			para13{"MCMXCIV"},
+			ans13{1994},
+		},
+
+		question13{
+			para13{"MCMXICIVI"},
+			ans13{2014},
+		},
+	}
+
+	fmt.Printf("------------------------Leetcode Problem 13------------------------\n")
+
+	for _, q := range qs {
+		_, p := q.ans13, q.para13
+		fmt.Printf("【input】:%v    【output】:%v\n", p.one, romanToInt(p.one))
+	}
+	fmt.Printf("\n\n\n")
+}

leetcode/0013.Roman-to-Integer/README.md

@@ -0,0 +1,132 @@
+# [13. Roman to Integer](https://leetcode.com/problems/roman-to-integer/)
+
+
+## 题目
+
+Roman numerals are represented by seven different symbols: `I`, `V`, `X`, `L`, `C`, `D` and `M`.
+
+```
+Symbol       Value
+I             1
+V             5
+X             10
+L             50
+C             100
+D             500
+M             1000
+```
+
+For example, two is written as `II` in Roman numeral, just two one's added together. Twelve is written as, `XII`, which is simply `X` + `II`. The number twenty seven is written as `XXVII`, which is `XX` + `V` + `II`.
+
+Roman numerals are usually written largest to smallest from left to right. However, the numeral for four is not `IIII`. Instead, the number four is written as `IV`. Because the one is before the five we subtract it making four. The same principle applies to the number nine, which is written as `IX`. There are six instances where subtraction is used:
+
+- `I` can be placed before `V` (5) and `X` (10) to make 4 and 9.
+- `X` can be placed before `L` (50) and `C` (100) to make 40 and 90.
+- `C` can be placed before `D` (500) and `M` (1000) to make 400 and 900.
+
+Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999.
+
+**Example 1**:
+
+```
+Input: "III"
+Output: 3
+```
+
+**Example 2**:
+
+```
+Input: "IV"
+Output: 4
+```
+
+**Example 3**:
+
+```
+Input: "IX"
+Output: 9
+```
+
+**Example 4**:
+
+```
+Input: "LVIII"
+Output: 58
+Explanation: L = 50, V= 5, III = 3.
+```
+
+**Example 5**:
+
+```
+Input: "MCMXCIV"
+Output: 1994
+Explanation: M = 1000, CM = 900, XC = 90 and IV = 4.
+```
+
+## 题目大意
+
+罗马数字包含以下七种字符: I， V， X， L，C，D 和 M。
+
+```go
+
+字符          数值
+I             1
+V             5
+X             10
+L             50
+C             100
+D             500
+M             1000
+
+```
+
+例如， 罗马数字 2 写做 II ，即为两个并列的 1。12 写做 XII ，即为 X + II 。 27 写做  XXVII, 即为 XX + V + II 。
+
+通常情况下，罗马数字中小的数字在大的数字的右边。但也存在特例，例如 4 不写做 IIII，而是 IV。数字 1 在数字 5 的左边，所表示的数等于大数 5 减小数 1 得到的数值 4 。同样地，数字 9 表示为 IX。这个特殊的规则只适用于以下六种情况：
+
+- I 可以放在 V (5) 和 X (10) 的左边，来表示 4 和 9。
+- X 可以放在 L (50) 和 C (100) 的左边，来表示 40 和 90。 
+- C 可以放在 D (500) 和 M (1000) 的左边，来表示 400 和 900。
+
+给定一个罗马数字，将其转换成整数。输入确保在 1 到 3999 的范围内。
+
+## 解题思路
+
+- 给定一个罗马数字，将其转换成整数。输入确保在 1 到 3999 的范围内。
+- 简单题。按照题目中罗马数字的字符数值，计算出对应罗马数字的十进制数即可。
+
+## 代码
+
+```go
+
+package leetcode
+
+var roman = map[string]int{
+	"I": 1,
+	"V": 5,
+	"X": 10,
+	"L": 50,
+	"C": 100,
+	"D": 500,
+	"M": 1000,
+}
+
+func romanToInt(s string) int {
+	if s == "" {
+		return 0
+	}
+	num, lastint, total := 0, 0, 0
+	for i := 0; i < len(s); i++ {
+		char := s[len(s)-(i+1) : len(s)-i]
+		num = roman[char]
+		if num < lastint {
+			total = total - num
+		} else {
+			total = total + num
+		}
+		lastint = num
+	}
+	return total
+}
+
+```