## Solved! Leetcode 63. Unique Paths II

source: https://leetcode.com/problems/unique-paths-ii/ Unique Paths II Table of ContentsUnique Paths IIDescriptionExample 1:Example 2:Constraints:Solution Description You are given an m x n integer array grid. There is a robot initially located at the top-left corner (i.e., grid). The robot tries to move to the bottom-right corner (i.e., grid[m – 1][n – 1]). The robot can only move ...

## Solved! Leetcode 1557. Minimum Number of Vertices to Reach All Nodes

source: https://leetcode.com/problems/minimum-number-of-vertices-to-reach-all-nodes/description/ Minimum Number of Vertices to Reach All Nodes Given a directed acyclic graph, with n vertices numbered from 0 to n-1, and an array edges where edges[i] = [fromi, toi] represents a directed edge from node fromi to node toi. Find the smallest set of vertices from which all nodes in the graph ...

## Solved! Leetcode 101. Symmetric Tree

source: https://leetcode.com/problems/symmetric-tree/description/ Symmetric Tree Given the root of a binary tree, check whether it is a mirror of itself (i.e., symmetric around its center). Example 1: Input: root = [1,2,2,3,4,4,3] Output: true Example 2: Input: root = [1,2,2,null,3,null,3] Output: false Constraints: The number of nodes in the tree is in the range [1, 1000]. -100 ...

## Solved! Leetcode 72. Edit Distance

source: https://leetcode.com/problems/edit-distance/ Edit Distance Given two strings word1 and word2, return the minimum number of operations required to convert word1 to word2. You have the following three operations permitted on a word: Insert a character Delete a character Replace a character Example 1: Input: word1 = “horse”, word2 = “ros” Output: 3 Explanation: horse -> ...