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import { TreeNode } from "../binary-tree-inorder-traversal/TreeNode.ts";
export default function smallestFromLeaf(root: TreeNode | null): string {    if (!root) return "";
    const strs: string[] = [];    let cur = [{ node: root, str: intToChar(root.val) }];    while (cur.length) {        const tem: typeof cur = [];
        for (const a of cur) {            if (!a.node.left && !a.node.right) {                strs.push(a.str);            }            if (a.node.left) {                tem.push({                    node: a.node.left,                    str: intToChar(a.node.left.val) + a.str,                });            }            if (a.node.right) {                tem.push({                    node: a.node.right,                    str: intToChar(a.node.right.val) + a.str,                });            }        }        if (tem.length) {            cur = tem;        } else {            break;        }    }
    return strs.reduce((a, v) => (a.localeCompare(v) < 0 ? a : v));}function intToChar(i: number) {    return String.fromCharCode(i + "a".charCodeAt(0));}