Merge pull request #825 from 0xff-dev/592

Add solution and test-cases for problem 592

Author: 6boris

leetcode/501-600/0592.Fraction-Addition-and-Subtraction/README.md

@@ -1,28 +1,30 @@
 # [592.Fraction Addition and Subtraction][title]
 
-> [!WARNING|style:flat]
-> This question is temporarily unanswered if you have good ideas. Welcome to [Create Pull Request PR](https://github.com/kylesliu/awesome-golang-algorithm)
-
 ## Description
+Given a string `expression` representing an expression of fraction addition and subtraction, return the calculation result in string format.
+
+The final result should be an [irreducible fraction](https://en.wikipedia.org/wiki/Irreducible_fraction). If your final result is an integer, change it to the format of a fraction that has a denominator `1`. So in this case, `2` should be converted to `2/1`.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: expression = "-1/2+1/2"
+Output: "0/1"
 ```
 
-## 题意
-> ...
+**Example 2:**
 
-## 题解
-
-### 思路1
-> ...
-Fraction Addition and Subtraction
-```go
+```
+Input: expression = "-1/2+1/2+1/3"
+Output: "1/3"
 ```
 
+**Example 3:**
+
+```
+Input: expression = "1/3-1/2"
+Output: "-1/6"
+```
 
 ## 结语
 

leetcode/501-600/0592.Fraction-Addition-and-Subtraction/Solution.go

@@ -1,5 +1,91 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+import "fmt"
+
+func gcd592(a, b int) int {
+	for b != 0 {
+		a, b = b, a%b
+	}
+	return a
+}
+
+func add592(a, b, c, d int) (int, int) {
+	denominator := b * d
+	numerator := a*d + b*c
+	lessZero := false
+	if numerator < 0 {
+		lessZero = true
+		numerator = -numerator
+	}
+	g := gcd592(numerator, denominator)
+	denominator /= g
+	numerator /= g
+	if lessZero {
+		numerator = -numerator
+	}
+
+	return numerator, denominator
+}
+func sub592(a, b, c, d int) (int, int) {
+
+	denominator := b * d
+	numerator := a*d - b*c
+	lessZero := false
+	if numerator < 0 {
+		lessZero = true
+		numerator = -numerator
+	}
+	g := gcd592(numerator, denominator)
+	denominator /= g
+	numerator /= g
+	if lessZero {
+		numerator = -numerator
+	}
+
+	return numerator, denominator
+}
+
+func Solution(expression string) string {
+	numerator, denominator := 0, 1
+	nums := 0
+	op := byte('+')
+	if expression[0] != '-' {
+		nums++
+	}
+	n, d := 0, 0
+	f := true
+	for index := 0; index < len(expression); index++ {
+		if expression[index] == '+' || expression[index] == '-' {
+			nums++
+			if nums == 2 {
+				if op == '+' {
+					numerator, denominator = add592(numerator, denominator, n, d)
+				} else {
+					numerator, denominator = sub592(numerator, denominator, n, d)
+				}
+				nums = 1
+			}
+
+			op = expression[index]
+			f = true
+			n, d = 0, 0
+			continue
+		}
+		if expression[index] == '/' {
+			f = false
+		}
+		if expression[index] >= '0' && expression[index] <= '9' {
+			if f {
+				n = n*10 + int(expression[index]-'0')
+			} else {
+				d = d*10 + int(expression[index]-'0')
+			}
+		}
+	}
+	if op == '+' {
+		numerator, denominator = add592(numerator, denominator, n, d)
+	} else {
+		numerator, denominator = sub592(numerator, denominator, n, d)
+	}
+	return fmt.Sprintf("%d/%d", numerator, denominator)
 }

leetcode/501-600/0592.Fraction-Addition-and-Subtraction/Solution_test.go

@@ -10,12 +10,12 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs string
+		expect string
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", "-1/2+1/2", "0/1"},
+		{"TestCase2", "-1/2+1/2+1/3", "1/3"},
+		{"TestCase3", "1/3-1/2", "-1/6"},
 	}
 
 	//	开始测试
@@ -30,10 +30,10 @@ func TestSolution(t *testing.T) {
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }