changed 494. Target Sum & Added solution 1963. Minimum Number of Swaps to Make the String Balanced

leetcode/0043.Multiply-Strings/43. Multiply Strings.go

@@ -1,25 +1,43 @@
+/*
+* Author: Sk Shahriar Ahmed Raka
+* Email: [email protected]
+ * Telegram: https://t.me/shahriarraka
+ * Github: https://github.com/skshahriarahmedraka
+ * StackOverflow: https://stackoverflow.com/users/12216779/
+ * Linkedin: https://linkedin.com/in/shahriarraka
+ * -----
+ * Last Modified:
+ * Modified By:
+ * -----
+ * Copyright (c) 2022 Your Company
+ * -----
+ * HISTORY:
+ */
+
+ // 311 / 311 test cases passed.
+ // Status: Accepted
+ // Runtime: 0 ms
+ // Memory Usage: 2.3 MB
+
+ // You are here!
+ // Your runtime beats 100.00 % of golang submissions.
+
+ // You are here!
+ // Your memory usage beats 77.90 % of golang submissions.
 package leetcode
 
+import (
+	"math/big"
+
+)
+
+
 func multiply(num1 string, num2 string) string {
-	if num1 == "0" || num2 == "0" {
-		return "0"
-	}
-	b1, b2, tmp := []byte(num1), []byte(num2), make([]int, len(num1)+len(num2))
-	for i := 0; i < len(b1); i++ {
-		for j := 0; j < len(b2); j++ {
-			tmp[i+j+1] += int(b1[i]-'0') * int(b2[j]-'0')
-		}
-	}
-	for i := len(tmp) - 1; i > 0; i-- {
-		tmp[i-1] += tmp[i] / 10
-		tmp[i] = tmp[i] % 10
-	}
-	if tmp[0] == 0 {
-		tmp = tmp[1:]
-	}
-	res := make([]byte, len(tmp))
-	for i := 0; i < len(tmp); i++ {
-		res[i] = '0' + byte(tmp[i])
-	}
-	return string(res)
+	var x big.Int
+	var y big.Int
+	var z big.Int 
+	x.SetString(num1,10)
+	y.SetString(num2,10)
+	z.Mul(&x,&y)
+	return z.String()
 }

leetcode/0494.Target-Sum/494. Target Sum.go

@@ -47,3 +47,35 @@ func dfsFindTargetSumWays(nums []int, index int, curSum int, S int, res *int, su
 	dfsFindTargetSumWays(nums, index+1, curSum+nums[index], S, res, sums)
 	dfsFindTargetSumWays(nums, index+1, curSum-nums[index], S, res, sums)
 }
+
+// recursive 
+func RecursivefindTargetSumWays(nums []int, target int) int {
+	//  Runtime: 611 ms, faster than 19.64% of Go online submissions for Target Sum.
+	//  Memory Usage: 2 MB, less than 97.26% of Go online submissions for Target Sum.
+	ans :=0
+	CurrentValue:=0 
+	var sum func(int,[]int)
+	sum =func (CurrentValue int, arr []int) {
+		if len(arr)==0 && CurrentValue==target {
+			ans+=1
+			return
+		}else if len(arr)==0 {
+			return
+		}
+		temp:=arr
+		if len(arr)==1{
+			temp=[]int{}
+		}else {
+			temp=arr[1:]
+		}
+
+		sum(CurrentValue+arr[0],temp)
+		sum(CurrentValue-arr[0],temp)
+
+
+	}
+
+	sum(CurrentValue,nums)
+	return ans 
+}
+

leetcode/0494.Target-Sum/README.md

@@ -105,4 +105,38 @@ func dfsFindTargetSumWays(nums []int, index int, curSum int, S int, res *int, su
 	dfsFindTargetSumWays(nums, index+1, curSum-nums[index], S, res, sums)
 }
 
-```
+```
+
+// recursive 
+```
+func RecursivefindTargetSumWays(nums []int, target int) int {
+	//  Runtime: 611 ms, faster than 19.64% of Go online submissions for Target Sum.
+	//  Memory Usage: 2 MB, less than 97.26% of Go online submissions for Target Sum.
+	ans :=0
+	CurrentValue:=0 
+	var sum func(int,[]int)
+	sum =func (CurrentValue int, arr []int) {
+		if len(arr)==0 && CurrentValue==target {
+			ans+=1
+			return
+		}else if len(arr)==0 {
+			return
+		}
+		temp:=arr
+		if len(arr)==1{
+			temp=[]int{}
+		}else {
+			temp=arr[1:]
+		}
+
+		sum(CurrentValue+arr[0],temp)
+		sum(CurrentValue-arr[0],temp)
+
+
+	}
+
+	sum(CurrentValue,nums)
+	return ans 
+}
+```
+

leetcode/1963. Minimum Number of Swaps to Make the String Balanced/Minimum Number of Swaps to Make the String Balanced.go

@@ -0,0 +1,55 @@
+package leetcode
+/*
+ * Author: Sk Shahriar Ahmed Raka
+ * Email: [email protected]
+ * Telegram: https://t.me/shahriarraka
+ * Github: https://github.com/skshahriarahmedraka
+ * StackOverflow: https://stackoverflow.com/users/12216779/
+ * Linkedin: https://linkedin.com/in/shahriarraka
+ * -----
+ * Last Modified:
+ * Modified By:
+ * -----
+ * Copyright (c) 2022 Your Company
+ * -----
+ * HISTORY:
+ */
+
+
+
+// 58 / 58 test cases passed.
+// Status: Accepted
+// Runtime: 42 ms
+// Memory Usage: 9.8 MB
+
+// Submitted: 0 minutes ago
+// Runtime: 42 ms, faster than 87.50% of Go online submissions for Minimum Number of Swaps to Make the String Balanced.
+// Memory Usage: 9.8 MB, less than 81.25% of Go online submissions for Minimum Number of Swaps to Make the String Balanced.
+
+
+
+
+
+func minSwaps(s string) int {
+	maxClose:=0
+	close:=0
+	for _,i:= range s {
+		if i=='['{
+			close-=1
+		}else {
+			close+=1
+		}
+		maxClose=MAX(maxClose,close)
+
+
+	}
+	return (maxClose+1)/2
+
+}
+
+func MAX(i,j int)int{
+	if i>j{
+		return i 
+	}
+	return j
+}

leetcode/1963. Minimum Number of Swaps to Make the String Balanced/README.md

@@ -0,0 +1,79 @@
+## 1963. Minimum Number of Swaps to Make the String Balanced
+### Medium
+
+You are given a 0-indexed string s of even length n. The string consists of exactly n / 2 opening brackets '[' and n / 2 closing brackets ']'.
+
+A string is called balanced if and only if:
+
+    It is the empty string, or
+    It can be written as AB, where both A and B are balanced strings, or
+    It can be written as [C], where C is a balanced string.
+
+You may swap the brackets at any two indices any number of times.
+
+Return the minimum number of swaps to make s balanced.
+
+
+
+Example 1:
+    Input: s = "][]["
+    Output: 1
+    Explanation: You can make the string balanced by swapping index 0 with index 3.
+    The resulting string is "[[]]".
+
+Example 2:
+    Input: s = "]]][[["
+    Output: 2
+    Explanation: You can do the following to make the string balanced:
+    - Swap index 0 with index 4. s = "[]][][".
+    - Swap index 1 with index 5. s = "[[][]]".
+    The resulting string is "[[][]]".
+
+Example 3:
+
+    Input: s = "[]"
+    Output: 0
+    Explanation: The string is already balanced.
+
+
+
+Constraints:
+
+    n == s.length
+    2 <= n <= 106
+    n is even.
+    s[i] is either '[' or ']'.
+    The number of opening brackets '[' equals n / 2, and the number of closing brackets ']' equals n / 2.
+
+Accepted
+32,547
+Submissions
+47,800
+
+
+## solution 
+```
+func minSwaps(s string) int {
+	maxClose:=0
+	close:=0
+	for _,i:= range s {
+		if i=='['{
+			close-=1
+		}else {
+			close+=1
+		}
+		maxClose=MAX(maxClose,close)
+
+
+	}
+	return (maxClose+1)/2
+
+}
+
+func MAX(i,j int)int{
+	if i>j{
+		return i 
+	}
+	return j
+}
+```