How Do I Know If I'm Making Progress With Leetcode?

It's demoralizing to get stuck on similar problems repeatedly. How do you know if you're making progress?

Course: <https://www.jointaro.com/course/crash-course-data-structures-and-algorithms-concepts/>

How To Apply The 80/20 Rule To Leetcode Prep

Even Alvin, who has mastery over Data Structures and Algorithms, would not pass all the tech interviews!

Course: <https://www.jointaro.com/course/crash-course-data-structures-and-algorithms-concepts/>

DSA Crash Course [Part 87] - Outro

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: <https://www.linkedin.com/in/alvin-zablan-b73a92117/>

DSA Crash Course [Part 86] - Array Stepper Walkthrough

In this lesson, Alvin walks through the python implementation for the *array_stepper* problem.

Code along and test your work in the following editor workspace: <https://structy.net/problems/array-stepper?language=py>

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: [**https://www.linkedin.com/in/alvin-zablan-b73a92117/**](https://www.linkedin.com/in/alvin-zablan-b73a92117/)

DSA Crash Course [Part 85] - Array Stepper Approach

In this lesson, Alvin explores the strategy to solving the following interview problem:

> Write a function, *array_stepper*, that takes in a list of numbers as an argument. You start at the first position of the list. The function should return a boolean indicating whether or not it is possible to reach the last position of the list. When situated at some position of the list, you may take a maximum number of steps based on the number at that position.
>
> For example, given:
>
> - idx =  0  1  2  3  4  5
> - numbers = \[2, 4, 2, 0, 0, 1\]
>
> The answer is True.
>
> We start at idx 0, we could take 1 step or 2 steps forward.
>
> The correct choice is to take 1 step to idx 1.
>
> Then take 4 steps forward to the end at idx 5.

```
array_stepper([2, 4, 2, 0, 0, 1]) # -> True
```

```
array_stepper([2, 3, 2, 0, 0, 1]) # -> False
```

```
array_stepper([3, 1, 3, 1, 0, 1]) # -> True
```

```
array_stepper([4, 1, 5, 1, 1, 1, 0, 4]) # -> True
```

```
array_stepper([4, 1, 2, 1, 1, 1, 0, 4]) # -> False
```

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: [**https://www.linkedin.com/in/alvin-zablan-b73a92117/**](https://www.linkedin.com/in/alvin-zablan-b73a92117/)

DSA Crash Course [Part 84] - Counting Change Walkthrough

In this lesson, Alvin walks through the python implementation for the *counting_change* problem.

Code along and test your work in the following editor workspace: <https://structy.net/problems/counting-change?language=py>

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: [**https://www.linkedin.com/in/alvin-zablan-b73a92117/**](https://www.linkedin.com/in/alvin-zablan-b73a92117/)

DSA Crash Course [Part 83] - Counting Change Approach

In this lesson, Alvin explores the strategy to solving the following interview problem:

> Write a function, *counting_change*, that takes in an amount and a list of coins. The function should return the number of different ways it is possible to make change for the given amount using the coins.
>
> You may reuse a coin as many times as necessary.
>
> For example,
>
> counting_change(4, \[1,2,3\]) -&gt; 4
>
> There are four different ways to make an amount of 4:
>
> 1\. 1 + 1 + 1 + 1
>
> 2\. 1 + 1 + 2
>
> 3\. 1 + 3
>
> 4\. 2 + 2

```
counting_change(4, [1, 2, 3]) # -> 4
```

```
counting_change(8, [1, 2, 3]) # -> 10
```

```
counting_change(24, [5, 7, 3]) # -> 5
```

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: [**https://www.linkedin.com/in/alvin-zablan-b73a92117/**](https://www.linkedin.com/in/alvin-zablan-b73a92117/)

DSA Crash Course [Part 82] - Summing Squares Walkthrough

In this lesson, Alvin walks through the python implementation for the *summing_squares* problem.

Code along and test your work in the following editor workspace: <https://structy.net/problems/summing-squares?language=py>

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: [**https://www.linkedin.com/in/alvin-zablan-b73a92117/**](https://www.linkedin.com/in/alvin-zablan-b73a92117/)

DSA Crash Course [Part 81] - Summing Squares Approach

In this lesson, Alvin explores the strategy to solving the following interview problem:

> Write a function, *summing_squares*, that takes a target number as an argument. The function should return the minimum number of perfect squares that sum to the target. A perfect square is a number of the form (i\*i) where i &gt;= 1.
>
> For example: 1, 4, 9, 16 are perfect squares, but 8 is not a perfect square.
>
> Given 12:
>
> summing_squares(12) -&gt; 3
>
> The minimum squares required for 12 is three, by doing 4 + 4 + 4.
>
> Another way to make 12 is 9 + 1 + 1 + 1, but that requires four perfect squares.

```
summing_squares(8) # -> 2
```

```
summing_squares(9) # -> 1
```

```
summing_squares(12) # -> 3
```

```
summing_squares(1) # -> 1
```

```
summing_squares(31) # -> 4
```

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: [**https://www.linkedin.com/in/alvin-zablan-b73a92117/**](https://www.linkedin.com/in/alvin-zablan-b73a92117/)

DSA Crash Course [Part 80] - Non Adjacent Sum Walkthrough

In this lesson, Alvin walks through the python implementation for the *non_adjacent_sum* problem.

Code along and test your work in the following editor workspace: <https://structy.net/problems/non-adjacent-sum?language=py>

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: [**https://www.linkedin.com/in/alvin-zablan-b73a92117/**](https://www.linkedin.com/in/alvin-zablan-b73a92117/)

DSA Crash Course [Part 79] - Non Adjacent Sum Approach

In this lesson, Alvin explores the strategy to solving the following interview problem:

> Write a function, *non_adjacent_sum*, that takes in a list of numbers as an argument. The function should return the maximum sum of non-adjacent items in the list. There is no limit on how many items can be taken into the sum as long as they are not adjacent.
>
> For example, given: \[2, 4, 5, 12, 7\]
>
> The maximum non-adjacent sum is 16, because 4 + 12. 4 and 12 are not adjacent in the list.

```
nums = [2, 4, 5, 12, 7]
non_adjacent_sum(nums) # -> 16
```

```
nums = [7, 5, 5, 12]
non_adjacent_sum(nums) # -> 19
```

```
nums = [7, 5, 5, 12, 17, 29]
non_adjacent_sum(nums) # -> 48
```

```
nums = [
72, 62, 10,  6, 20, 19, 42,
46, 24, 78, 30, 41, 75, 38,
23, 28, 66, 55, 12, 17, 9,
12, 3, 1, 19, 30, 50, 20
]

non_adjacent_sum(nums) # -> 488
```

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: [**https://www.linkedin.com/in/alvin-zablan-b73a92117/**](https://www.linkedin.com/in/alvin-zablan-b73a92117/)

DSA Crash Course [Part 78] - Max Path Sum Walkthrough

In this lesson, Alvin walks through the python implementation for the *max_path_sum* problem.

Code along and test your work in the following editor workspace: <https://structy.net/problems/max-path-sum?language=py>

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: [**https://www.linkedin.com/in/alvin-zablan-b73a92117/**](https://www.linkedin.com/in/alvin-zablan-b73a92117/)

DSA Crash Course [Part 77] - Max Path Sum Approach

In this lesson, Alvin explores the strategy to solving the following interview problem:

> Write a function, *max_path_sum*, that takes in a grid as an argument. The function should return the maximum sum possible by traveling a path from the top-left corner to the bottom-right corner. You may only travel through the grid by moving down or right.
>
> You can assume that all numbers are non-negative.

```
grid = [
[1, 3, 12],
[5, 1, 1],
[3, 6, 1],
]

max_path_sum(grid) # -> 18
```

```
grid = [
[1, 2, 8,  1],
[3, 1, 12, 10],
[4, 0, 6,  3],
]

max_path_sum(grid) # -> 36
```

```
grid = [
[1, 2, 8, 1],
[3, 10, 12, 10],
[4, 0, 6, 3],
]

max_path_sum(grid) # -> 39
```

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: [**https://www.linkedin.com/in/alvin-zablan-b73a92117/**](https://www.linkedin.com/in/alvin-zablan-b73a92117/)

DSA Crash Course [Part 76] - Counts Paths Walkthrough

In this lesson, Alvin walks through the python implementation for the *count_paths* problem.

Code along and test your work in the following editor workspace: <https://structy.net/problems/count-paths?language=py>

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: [**https://www.linkedin.com/in/alvin-zablan-b73a92117/**](https://www.linkedin.com/in/alvin-zablan-b73a92117/)

DSA Crash Course [Part 75] - Count Paths Approach

In this lesson, Alvin explores the strategy to solving the following interview problem:

> Write a function, *count_paths*, that takes in a grid as an argument. In the grid, 'X' represents walls and 'O' represents open spaces. You may only move down or to the right and cannot pass through walls. The function should return the number of ways possible to travel from the top-left corner of the grid to the bottom-right corner.

```
grid = [
["O", "O"],
["O", "O"],
]

count_paths(grid) # -> 2
```

```
grid = [
["O", "O", "X"],
["O", "O", "O"],
["O", "O", "O"],
]

count_paths(grid) # -> 5
```

```
grid = [
["O", "O", "O"],
["O", "O", "X"],
["O", "O", "O"],
]

count_paths(grid) # -> 3
```

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: [**https://www.linkedin.com/in/alvin-zablan-b73a92117/**](https://www.linkedin.com/in/alvin-zablan-b73a92117/)

DSA Crash Course [Part 74] - Minimum Change Walkthrough

In this lesson, Alvin walks through the python implementation for the *min_change* problem.

Code along and test your work in the following editor workspace: <https://structy.net/problems/min-change?language=py>

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: [**https://www.linkedin.com/in/alvin-zablan-b73a92117/**](https://www.linkedin.com/in/alvin-zablan-b73a92117/)

DSA Crash Course [Part 73] - Minimum Change Approach

In this lesson, Alvin explores the strategy to solving the following interview problem:

> Write a function *min_change* that takes in an amount and a list of coins. The function should return the minimum number of coins required to create the amount. You may use each coin as many times as necessary.
>
> If it is not possible to create the amount, then return -1.

```
min_change(8, [1, 5, 4, 12]) # -> 2, because 4+4 is the minimum coins possible
```

```
min_change(13, [1, 9, 5, 14, 30]) # -> 5
```

```
min_change(23, [2, 5, 7]) # -> 4
```

```
min_change(102, [1, 5, 10, 25]) # -> 6
```

```
min_change(200, [1, 5, 10, 25]) # -> 8
```

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: [**https://www.linkedin.com/in/alvin-zablan-b73a92117/**](https://www.linkedin.com/in/alvin-zablan-b73a92117/)

DSA Crash Course [Part 72] - Sum Possible Walkthrough

In this lesson, Alvin walks through the python implementation for the *sum_possible* problem.

Code along and test your work in the following editor workspace: <https://structy.net/problems/sum-possible?language=py>

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: [**https://www.linkedin.com/in/alvin-zablan-b73a92117/**](https://www.linkedin.com/in/alvin-zablan-b73a92117/)

DSA Crash Course [Part 71] - Sum Possible Approach

In this lesson, Alvin explores the strategy to solving the following interview problem:

> Write a function *sum_possible* that takes in an amount and a list of positive numbers. The function should return a boolean indicating whether or not it is possible to create the amount by summing numbers of the list. You may reuse numbers of the list as many times as necessary.
>
> You may assume that the target amount is non-negative.

```
sum_possible(8, [5, 12, 4]) # -> True, 4 + 4
```

```
sum_possible(15, [6, 2, 10, 19]) # -> False
```

```
sum_possible(13, [6, 2, 1]) # -> True
```

```
sum_possible(103, [6, 20, 1]) # -> True
```

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: [**https://www.linkedin.com/in/alvin-zablan-b73a92117/**](https://www.linkedin.com/in/alvin-zablan-b73a92117/)

DSA Crash Course [Part 70] - Tribonacci Walkthrough

In this lesson, Alvin walks through the python implementation for the *tribonacci* problem.

Code along and test your work in the following editor workspace: <https://structy.net/problems/tribonacci?language=py>

If you need additional support taking these DSA skills and actually applying them, take [**Alvin's**](https://www.linkedin.com/in/alvin-zablan-b73a92117/) *complete* data structures and algorithms course on [**Structy**](https://structy.net/?utm_source=taro). You can try out the concepts yourself in their interactive code editor and learn advanced DSA patterns like stack exhaustive recursion.

Use [**this link to get 20% off**](https://structy.net/purchase?promo_code=taro20) the entire Structy DSA learning experience.

Follow Alvin on LinkedIn: [**https://www.linkedin.com/in/alvin-zablan-b73a92117/**](https://www.linkedin.com/in/alvin-zablan-b73a92117/)

Tech Career Growth Videos

Our instructional videos provide software engineers with insights needed for career growth. Masterclasses go incredibly in-depth on a specific tech topic while case studies are real examples from established engineering leaders.