作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 减去相交部分 参考资料 日期 题目地址:https://leetcode.com/problems/island-perimeter/description/ 题目描述 You are given a map in form of a two-dimensional integer grid where 1 represents land and 0…

You are given a map in form of a two-dimensional integer grid where 1 represents land and 0 represents water. Grid cells are connected horizontally/vertically (not diagonally). The grid is completely surrounded by water, and there is exactly one isla…

题目: 以二维数组形式表示坐标岛屿,求边长. 例子: [[0,1,0,0], [1,1,1,0], [0,1,0,0], [1,1,0,0]] Answer: 16 Explanation: The perimeter is the 16 yellow stripes in the image below: 思路:  一开始想用最笨的办法,就是两次for循环遍历所有元素,如果为1(1为岛屿),就分别判断 上.下.左.右 是否为岛屿,若不是则 边数+1 . 第二次换了想法, 每一条横向 如果有岛屿…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 排序 日期 题目地址:https://leetcode.com/problems/largest-perimeter-triangle/ 题目描述 Given an array A of positive lengths, return the largest perimeter of a triangle with non-zero area, f…

题目如下: Given an array A of positive lengths, return the largest perimeter of a triangle with non-zero area, formed from 3 of these lengths. If it is impossible to form any triangle of non-zero area, return 0. Example 1: Input: [2,1,2] Output: 5 Exampl…

[LeetCode]Island Perimeter 解题报告 [LeetCode] https://leetcode.com/problems/island-perimeter/ Total Accepted: 16143 Total Submissions: 28552 Difficulty: Easy Question You are given a map in form of a two-dimensional integer grid where 1 represents land…

Question 463. Island Perimeter Solution 题目大意:给出一个二维数组1表示陆地0表示海,求陆地的周长 思路: 重新构造一张地图grid2即一个二维数组,比原数组大一圈,即长宽都大2 一个点在原地图坐标是(i,j),那么在重新构造的坐标就是(i+1,j+1) 遍历原地图,如果一是陆地,就遍历这个点的周围是否是海,如果是海线周长就加1 Java实现: public int islandPerimeter(int[][] grid) { int total = 0…

[LeetCode]Minimum Depth of Binary Tree Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node. 递归和非递归,此提比较简单.广度优先遍历即可.关键之处就在于如何保持访问深度. 下面是4种代码: im…

Given an index k, return the kth row of the Pascal's triangle. For example, given k = 3, Return [1,3,3,1]. Note: Could you optimize your algorithm to use only O(k) extra space? 思路:最简单的方法就是依照[Leetcode]Pascal's Triangle 的方式自顶向下依次求解,但会造成空间的浪费.若仅仅用一个vect…

53. Maximum Subarray[leetcode] Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example, given the array [-2,1,-3,4,-1,2,1,-5,4],the contiguous subarray [4,-1,2,1] has the largest sum = 6. 挑…