算法是越学越得劲啊，思路开阔到不行
let res1 = false;
var fn2 = (root) => {
const stack = [root];
while (stack.length) {
const {head, sum} = stack.pop();
if(!head.left && !head.right && sum === 22){
res1 = true
}
const left = head.left;
const right = head.right;
if(right) stack.push({head: right, sum: sum + right.val});
if(left) stack.push({head: left, sum: sum + left.val});
}
}
fn2({head: binary, sum: binary.val})