wlhwaii的博客

题目 给定一个二叉树和一个目标和，找到所有从根节点到叶子节点路径总和等于给定目标和的路径。 说明：叶子节点是指没有子节点的节点。 示例： 给定如下二叉树，以及目标和 sum = 22， 5 / \ 4 8 / / \ 11 13 4 / \ / \ 7 2 5 ...

题目 给定一个根为 root 的二叉树，每个结点的深度是它到根的最短距离。 如果一个结点在整个树的任意结点之间具有最大的深度，则该结点是最深的。 一个结点的子树是该结点加上它的所有后代的集合。 返回能满足“以该结点为根的子树中包含所有最深的结点”这一条件的具有最大深度的结点。 示例： 输入：[3,5,1,6,2,0,8,null,null,7,4] 输出：[2,7,4] 解释： ...

题目 Starting with a positive integer N, we reorder the digits in any order (including the original order) such that the leading digit is not zero. Return true` if and only if we can do this in a way ...

题目 Given a function rand7 which generates a uniform random integer in the range 1 to 7, write a function rand10 which generates a uniform random integer in the range 1 to 10. Do NOT use system’s Mat...

题目 A car travels from a starting position to a destination which is target miles east of the starting position. Along the way, there are gas stations. Each stations[i] represents a gas station that...

题目 Given two arrays A and B of equal size, the advantage of A with respect to B is the number of indices i for which A[i] > B[i]. Return any permutation of A that maximizes its advantage with res...

题目 A sequence X_1, X_2, ..., X_n is fibonacci-like if: n >= 3 X_i + X_{i+1} = X_{i+2} for all i + 2 <= n Given a strictly increasing array A of positive integers forming a sequence, find the...

题目 Validate if a given string can be interpreted as a decimal number. Some examples: "0" => true " 0.1 " => true "abc" => false "1 a" => false "2e10" => true " -90e3