ad sol

leetcode/67.AddBinary/addBinary.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+	"fmt"
+)
+
+func addBinary(a string, b string) string {
+	result := ""
+
+	// 2 pointers
+	i := len(a) - 1
+	j := len(b) - 1
+
+	var carry byte = 0
+
+	for i >= 0 || j >= 0 || carry == 1 {
+		if i >= 0 {
+			carry += a[i] - '0'
+		}
+		if j >= 0 {
+			carry += b[j] - '0'
+		}
+
+		result = string(carry%2+'0') + result
+		carry = carry / 2
+		i--
+		j--
+	}
+
+	return result
+}
+
+func addBinary1(a string, b string) string {
+	i, j := len(a)-1, len(b)-1
+	result := []byte{}
+
+	for carry := 0; i >= 0 || j >= 0 || carry > 0; i, j = i-1, j-1 {
+		if i >= 0 {
+			carry += int(a[i] - '0')
+		}
+		if j >= 0 {
+			carry += int(b[j] - '0')
+		}
+		result = append(result, byte(carry%2+'0'))
+		carry /= 2
+	}
+
+	for i, j := 0, len(result)-1; i < j; i, j = i+1, j-1 {
+		result[i], result[j] = result[j], result[i]
+	}
+
+	return string(result)
+}
+
+func main() {
+	a := "11"
+	b := "1"
+
+	fmt.Println(addBinary(a, b))
+}