Week 06 - Intervals + Backtracking (Guide)

Reference extracted from the detailed guide.

Intervals

Backtracking

Watch First:

• NeetCode: Backtracking → https://www.youtube.com/watch?v=pfiQ_PS1g8E

Template: Backtracking

def subsets(nums):
    result = []
    
    def backtrack(start, path):
        result.append(path[:])  # add copy
        for i in range(start, len(nums)):
            path.append(nums[i])
            backtrack(i + 1, path)
            path.pop()
    
    backtrack(0, [])
    return result

def permute(nums):
    result = []
    
    def backtrack(path, used):
        if len(path) == len(nums):
            result.append(path[:])
            return
        for i in range(len(nums)):
            if used[i]:
                continue
            used[i] = True
            path.append(nums[i])
            backtrack(path, used)
            path.pop()
            used[i] = False
    
    backtrack([], [False] * len(nums))
    return result

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