Learn and practice the Backtracking and Subsets patterns to solve coding interview problems.

Educative-99 in JavaScript: Accelerate Your Coding Interview Prep

The optimal solution to certain problems requires examining all possibilities. If any possibility is ignored, we are unable to say with mathematical certainty that our solution is optimal. In such situations, we use a technique known as backtracking to exhaustively traverse the entire solution space and collect all the information needed to compute the optimal solution. The Subsets pattern groups together those problems where we need to systematically construct all, or, a mathematically defined subset of all, the possible subsets of a given set. Again, the technique used for the construction of such a set of subsets is, in fact, backtracking.

Go With the Flow

# Statement

Given a chessboard of size $n \times n$, determine how many ways $n$ queens can be placed on the board, such that no two queens attack each other.

A queen can move horizontally, vertically, and diagonally on a chessboard. One queen can be attacked by another queen if both share the same row, column, or diagonal.

**Constraints:**
- $1 \leq n \leq 9$
# Examples


Backtracking

Subsets

Conclusion

N-Queens

Statement