# Advanced Array-Based Problem-Solving with LeetCode Examples in Go.

Array-based problems on platforms like LeetCode often require advanced problem-solving techniques. Let's explore some challenging problems along with their solutions in Go.

## **Problem 1: Two Sum**

Given an array of integers `nums` and an integer `target`, return indices of the two numbers such that they add up to the `target`.

### **Solution:**

```go
func twoSum(nums []int, target int) []int {
    numMap := make(map[int]int)
    for i, num := range nums {
        complement := target - num
        if index, ok := numMap[complement]; ok {
            return []int{index, i}
        }
        numMap[num] = i
    }
    return nil
}
```

## **Problem 2: Maximum Subarray**

Given an integer array `nums`, find the contiguous subarray (containing at least one number) that has the largest sum and return its sum.

### **Solution:**

```go
func maxSubArray(nums []int) int {
    maxSum, currentSum := nums[0], nums[0]
    for i := 1; i < len(nums); i++ {
        currentSum = max(nums[i], currentSum+nums[i])
        maxSum = max(maxSum, currentSum)
    }
    return maxSum
}

func max(a, b int) int {
    if a > b {
        return a
    }
    return b
}
```

## **Problem 3: Product of Array Except for Self**

Given an integer array `nums`, return an array `output` such that `output[i]` is equal to the product of all the elements of `nums` except `nums[i]`.

### **Solution:**

```go
func productExceptSelf(nums []int) []int {
    length := len(nums)
    left, right := make([]int, length), make([]int, length)
    left[0], right[length-1] = 1, 1

    for i := 1; i < length; i++ {
        left[i] = left[i-1] * nums[i-1]
        right[length-i-1] = right[length-i] * nums[length-i]
    }

    for i := 0; i < length; i++ {
        left[i] *= right[i]
    }
    return left
}
```

## **Problem 4: Rotate Array**

Given an array, rotate the array to the right by `k` steps, where `k` is non-negative.

### **Solution:**

```go
func rotate(nums []int, k int) {
    k %= len(nums)
    reverse(nums)
    reverse(nums[:k])
    reverse(nums[k:])
}

func reverse(nums []int) {
    left, right := 0, len(nums)-1
    for left < right {
        nums[left], nums[right] = nums[right], nums[left]
        left++
        right--
    }
}
```

## **Problem 5: Set Matrix Zeroes**

Given an `m x n` matrix, if an element is `0`, set its entire row and column to `0`. Do it in place.

### **Solution:**

```go
func setZeroes(matrix [][]int) {
    m, n := len(matrix), len(matrix[0])
    rows, cols := make(map[int]bool), make(map[int]bool)

    for i := 0; i < m; i++ {
        for j := 0; j < n; j++ {
            if matrix[i][j] == 0 {
                rows[i] = true
                cols[j] = true
            }
        }
    }

    for i := 0; i < m; i++ {
        for j := 0; j < n; j++ {
            if rows[i] || cols[j] {
                matrix[i][j] = 0
            }
        }
    }
}
```

## **Conclusion**

LeetCode problems often challenge developers to employ advanced problem-solving skills using arrays in Go. These solutions showcase efficient approaches to tackle diverse array-related problems. Practicing these problems enhances problem-solving abilities and strengthens proficiency in handling arrays in Go, preparing developers to solve a wide array of computational challenges effectively.

I hope this helps, you!!

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