027-tree-sum

tree sum

Write a function, treeSum, that takes in the root of a binary tree that contains number values. The function should return the total sum of all values in the tree.

test_00:

const a = new Node(3);
const b = new Node(11);
const c = new Node(4);
const d = new Node(4);
const e = new Node(-2);
const f = new Node(1);

a.left = b;
a.right = c;
b.left = d;
b.right = e;
c.right = f;

//       3
//    /    \
//   11     4
//  / \      \
// 4   -2     1

treeSum(a); // -> 21

test_01:

const a = new Node(1);
const b = new Node(6);
const c = new Node(0);
const d = new Node(3);
const e = new Node(-6);
const f = new Node(2);
const g = new Node(2);
const h = new Node(2);

a.left = b;
a.right = c;
b.left = d;
b.right = e;
c.right = f;
e.left = g;
f.right = h;

//      1
//    /   \
//   6     0
//  / \     \
// 3   -6    2
//    /       \
//   2         2

treeSum(a); // -> 10

test_02:

treeSum(null); // -> 0