Cheat Sheet

Backtracking Cheat Sheet

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What is Backtracking?

Explore all possibilities with systematic trial and error.

Trigger Words

When you see these in a problem, think Backtracking:

subsets backtracking combination sum permutations subsets ii combination sum ii word search palindrome partitioning n-queens

Template Code

def subsets(nums: List[int]) -> List[List[int]]:
    result = []
    
    def backtrack(start, current):
        result.append(current[:])
        
        for i in range(start, len(nums)):
            current.append(nums[i])
            backtrack(i + 1, current)
            current.pop()
    
    backtrack(0, [])
    return result

Complexity

Typical Time	`O(n * 2^n)`
Typical Space	`O(n)`

Common Variations

Basic Backtracking
Backtracking with constraints
Optimized Backtracking

Practice Problems

Subsets hard Combination Sum hard Permutations hard Subsets II hard Combination Sum II hard

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Practice Backtracking

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