🚀 FAANG-Style Problem Solving Framework Explained with Example: “Find First and Last Position in Sorted Array”

Author: Abdullah Abdelhakeem Published on: PCodeCamp Learn Problem Solving & System Design Like a Pro Difficulty: Medium | Category: Binary Search | Company Tags: Amazon, Meta, Google, Netflix, Microsoft

🧠 The FAANG / MAANG Problem-Solving Framework

To crack top Big Tech interviews (FAANG or MAANG), every coding solution should follow a structured framework. Here’s the 7-step FAANG Framework we teach at PCodeCamp for mastering Problem Solving and System Design Thinking:

This structure is how Big Tech engineers approach every coding problem — methodical, clear, and optimized.

💡 Example Problem: Find First and Last Position of Element in Sorted Array

Problem Statement: Given a sorted array of integers nums and a target value, find the first and last index of that target. If not found, return [-1, -1].

Constraints:

• Array can be empty.
• Must run in O(log n).
• Use binary search logic.

🧩 Step-by-Step FAANG Breakdown

1. Understand the Problem

We need to locate both the first and last positions of a given target in a sorted array.

2. Ask Clarifying Questions

3. Edge Cases

4. Work Through Examples

5. Idea Visualization

Use two binary searches:

• First search → move left on match (find first occurrence).
• Second search → move right on match (find last occurrence).

6. Code Implementation (Optimized O(log n))

class Solution {
public:
    vector<int> searchRange(vector<int>& nums, int target) {
        auto findPosition = [&](bool findFirst) {
            int left = 0, right = nums.size() - 1, pos = -1;
            while (left <= right) {
                int mid = left + (right - left) / 2;
                if (nums[mid] == target) {
                    pos = mid;
                    if (findFirst) right = mid - 1;
                    else left = mid + 1;
                } 
                else if (nums[mid] < target)
                    left = mid + 1;
                else
                    right = mid - 1;
            }
            return pos;
        };
        
        int first = findPosition(true);
        int last = findPosition(false);
        return {first, last};
    }
};        

7. Trace the Example

nums = [5,7,7,8,8,10], target = 8
→ first = 3, last = 4
Output: [3,4]        

8. Complexity Analysis

9. Memory Layout (for Deep Learners)

🏁 Final Takeaways

✅ Structured approach like this mirrors how FAANG engineers solve problems.

✅ Every solution is a story — from understanding to optimization.

✅ Practice this framework until it becomes muscle memory.

✨ Next Steps for Learners

• 🔹 Join PCodeCamp’s weekly Mock Interview Sprint to practice under FAANG standards.