规范格式

leetcode/0224.Basic-Calculator/224. Basic Calculator.go

@@ -0,0 +1,120 @@
+package leetcode
+
+import (
+	"container/list"
+	"fmt"
+	"strconv"
+)
+
+// 解法一
+func calculate(s string) int {
+	i, stack, result, sign := 0, list.New(), 0, 1 // 记录加减状态
+	for i < len(s) {
+		if s[i] == ' ' {
+			i++
+		} else if s[i] <= '9' && s[i] >= '0' { // 获取一段数字
+			base, v := 10, int(s[i]-'0')
+			for i+1 < len(s) && s[i+1] <= '9' && s[i+1] >= '0' {
+				v = v*base + int(s[i+1]-'0')
+				i++
+			}
+			result += v * sign
+			i++
+		} else if s[i] == '+' {
+			sign = 1
+			i++
+		} else if s[i] == '-' {
+			sign = -1
+			i++
+		} else if s[i] == '(' { // 把之前计算结果及加减状态压栈，开始新的计算
+			stack.PushBack(result)
+			stack.PushBack(sign)
+			result = 0
+			sign = 1
+			i++
+		} else if s[i] == ')' { // 新的计算结果 * 前一个加减状态 + 之前计算结果
+			result = result*stack.Remove(stack.Back()).(int) + stack.Remove(stack.Back()).(int)
+			i++
+		}
+	}
+	return result
+}
+
+// 解法二
+func calculate1(s string) int {
+	stack := []byte{}
+	for i := 0; i < len(s); i++ {
+		if s[i] == ' ' {
+			continue
+		} else if s[i] == ')' {
+			tmp, index := "", len(stack)-1
+			for ; index >= 0; index-- {
+				if stack[index] == '(' {
+					break
+				}
+			}
+			tmp = string(stack[index+1 : len(stack)])
+			stack = stack[:index]
+			res := strconv.Itoa(calculateStr(tmp))
+			for j := 0; j < len(res); j++ {
+				stack = append(stack, res[j])
+			}
+		} else {
+			stack = append(stack, s[i])
+		}
+	}
+	fmt.Printf("stack = %v\n", string(stack))
+	return calculateStr(string(stack))
+}
+
+func calculateStr(str string) int {
+	s, nums, tmpStr, res := []byte{}, []int{}, "", 0
+	// 处理符号的问题，++得+，--得+，+-、-+得-
+	for i := 0; i < len(str); i++ {
+		if len(s) > 0 && s[len(s)-1] == '+' && str[i] == '+' {
+			continue
+		} else if len(s) > 0 && s[len(s)-1] == '+' && str[i] == '-' {
+			s[len(s)-1] = '-'
+		} else if len(s) > 0 && s[len(s)-1] == '-' && str[i] == '+' {
+			continue
+		} else if len(s) > 0 && s[len(s)-1] == '-' && str[i] == '-' {
+			s[len(s)-1] = '+'
+		} else {
+			s = append(s, str[i])
+		}
+	}
+	str = string(s)
+	s = []byte{}
+	for i := 0; i < len(str); i++ {
+		if isDigital(str[i]) {
+			tmpStr += string(str[i])
+		} else {
+			num, _ := strconv.Atoi(tmpStr)
+			nums = append(nums, num)
+			tmpStr = ""
+			s = append(s, str[i])
+		}
+	}
+	if tmpStr != "" {
+		num, _ := strconv.Atoi(tmpStr)
+		nums = append(nums, num)
+		tmpStr = ""
+	}
+	res = nums[0]
+	for i := 0; i < len(s); i++ {
+		if s[i] == '+' {
+			res += nums[i+1]
+		} else {
+			res -= nums[i+1]
+		}
+	}
+	fmt.Printf("s = %v nums = %v res = %v\n", string(s), nums, res)
+	return res
+}
+
+func isDigital(v byte) bool {
+	if v >= '0' && v <= '9' {
+		return true
+	}
+	return false
+}

leetcode/0224.Basic-Calculator/224. Basic Calculator_test.go

@@ -0,0 +1,56 @@
+package leetcode
+
+import (
+	"fmt"
+	"testing"
+)
+
+type question224 struct {
+	para224
+	ans224
+}
+
+// para 是参数
+// one 代表第一个参数
+type para224 struct {
+	one string
+}
+
+// ans 是答案
+// one 代表第一个答案
+type ans224 struct {
+	one int
+}
+
+func Test_Problem224(t *testing.T) {
+
+	qs := []question224{
+
+		question224{
+			para224{"1 + 1"},
+			ans224{2},
+		},
+		question224{
+			para224{" 2-1 + 2 "},
+			ans224{3},
+		},
+
+		question224{
+			para224{"(1+(4+5+2)-3)+(6+8)"},
+			ans224{23},
+		},
+
+		question224{
+			para224{"2-(5-6)"},
+			ans224{3},
+		},
+	}
+
+	fmt.Printf("------------------------Leetcode Problem 224------------------------\n")
+
+	for _, q := range qs {
+		_, p := q.ans224, q.para224
+		fmt.Printf("【input】:%v       【output】:%v\n", p, calculate(p.one))
+	}
+	fmt.Printf("\n\n\n")
+}

leetcode/0224.Basic-Calculator/README.md

@@ -0,0 +1,38 @@
+# [224. Basic Calculator](https://leetcode.com/problems/basic-calculator/)
+
+
+## 题目
+
+Implement a basic calculator to evaluate a simple expression string.
+
+The expression string may contain open `(` and closing parentheses `)`, the plus `+` or minus sign `-`, **non-negative** integers and empty spaces .
+
+**Example 1:**
+
+    Input: "1 + 1"
+    Output: 2
+
+**Example 2:**
+
+    Input: " 2-1 + 2 "
+    Output: 3
+
+**Example 3:**
+
+    Input: "(1+(4+5+2)-3)+(6+8)"
+    Output: 23
+
+**Note:**
+
+- You may assume that the given expression is always valid.
+- **Do not** use the `eval` built-in library function.
+
+## 题目大意
+
+实现一个基本的计算器来计算一个简单的字符串表达式的值。字符串表达式可以包含左括号 ( ，右括号 )，加号 + ，减号 -，非负整数和空格  。
+
+## 解题思路
+
+- 注意点一：算式中有空格，需要跳过
+- 注意点二：算式中会出现负数，负负得正的情况需要特殊处理，所以需要记录每次计算出来的符号
+