描述 给一个01矩阵,求不同的岛屿的个数. 0代表海,1代表岛,如果两个1相邻,那么这两个1属于同一个岛.我们只考虑上下左右为相邻. 样例 在矩阵: [ [1, 1, 0, 0, 0], [0, 1, 0, 0, 1], [0, 0, 0, 1, 1], [0, 0, 0, 0, 0], [0, 0, 0, 0, 1] ] 中有 3 个岛. 代码 GitHub 的源代码,请访问下面的链接: https://github.com/cwiki-us/java-tutorial/blob/master…

Given a boolean 2D matrix, find the number of islands. Notice 0 is represented as the sea, 1 is represented as the island. If two 1 is adjacent, we consider them in the same island. We only consider up/down/left/right adjacent. Have you met this ques…

A typical Union-Find one. I'm using a kinda Union-Find solution here. Some boiler-plate code - yeah I know. class Solution { unordered_set<int> hs; // start from 1 int max_k; public: void dfs(vector<vector<int>> &mt, int x, int y, in…

分析:经典连通分量问题 图: 节点:所有1的位置 边:两个相邻的1的位置有一条边 BFS/DFS (DFS使用递归,代码较短) 选一个没标记的点,然后搜索,扩展4个邻居(如果有),直到不能扩展 每一次是一个连通分量 难点:标记节点——判重 C++ DFS class Solution { public: void help(vector<vector<bool>>& a, int x, int y) { ) || (x >= a.size()) || (y <…

LintCode 433. 岛屿的个数(Number of Islands) 代码: class Solution: """ @param grid: a boolean 2D matrix @return: an integer """ def numIslands(self, grid): # write your code here n_Islands=0 n_rows=len(grid) if n_rows: n_cols=len(gri…

Description Given a boolean 2D matrix, 0 is represented as the sea, 1 is represented as the island. If two 1 is adjacent, we consider them in the same island. We only consider up/down/left/right adjacent. Find the number of islands. Example Given gra…

两种方式处理已经访问过的节点:一种是用visited存储已经访问过的1:另一种是通过改变原始数值的值,比如将1改成-1,这样小于等于0的都会停止. Number of Islands 用了第一种方式,Number of Distinct Islands用了第二种方式 200. Number of Islands 时间复杂度o(m*n) 1.这种写法要改变原始输入数组的值 错误版本: 条件判断顺序写错:grid[x][y] == '0' || x < 0 || x >= length || y…

A 2d grid map of m rows and n columns is initially filled with water. We may perform an addLand operation which turns the water at position (row, col) into a land. Given a list of positions to operate, count the number of islands after each addLand o…

Given a 2d grid map of '1's (land) and '0's (water), count the number of islands. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. You may assume all four edges of the grid are all surrounded by…

Given a 2d grid map of '1's (land) and '0's (water), count the number of islands. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. You may assume all four edges of the grid are all surrounded by…