# LeetCode: Symmetric Tree Solution

*Recursion*

## Approach

Base cases:

- falsewhen either left or right is null
- truewhen both left and right are null
- falsewhen both values of left and right are not equal

## Implementation

1var isSymmetric = function (root) {2 if (!root) return true34 const recursion = (left, right) => {5 if ((!left && right) || (left && !right)) return false6 if (!left && !right) return true7 if (left.val !== right.val) return false8 return (9 recursion(left.left, right.right) && recursion(left.right, right.left)10 )11 }1213 return recursion(root.left, root.right)14}

## References

## Comments

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## Tags

leetcode

tree

binary tree

recursion

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