岛屿的个数

题目

public class Solution {
    /**
     * @param grid: a boolean 2D matrix
     * @return: an integer
     */
    public int numIslands(boolean[][] grid) {
        // write your code here
        int sum = 0;
        for(int x = 0;x<grid.length;x++){
            for(int y = 0 ; y<grid[x].length;y++){
                if(grid[x][y]){
                    sum++;
                    grid[x][y] = false;
                    removeSame(grid,x,y);
                }
            }
        }
        return sum;
    }
    
    public void removeSame(boolean[][] grid,int x, int y){
        for(int i = x+1;i<grid.length;i++){
            if(grid[i][y]){
                grid[i][y] = false;
                removeSame(grid,i,y);
            }else{
                break;
            }
        }
        for(int i = x-1;i>=0;i--){
            if(grid[i][y]){
                grid[i][y] = false;
                removeSame(grid,i,y);
            }else{
                break;
            }
        }
        for(int i = y+1;i<grid[x].length;i++){
            if(grid[x][i]){
                grid[x][i] = false;
                removeSame(grid,x,i);
            }else{
                break;
            }
        }
        for(int i = y-1;i>=0;i--){
            if(grid[x][i]){
                grid[x][i] = false;
                removeSame(grid,x,i);
            }else{
                break;
            }
        }
    }
}

思路：搜索到陆地(1)以后向前后以及下方遍历直至搜到海(0)，将搜索到的陆地全部置为0并且将岛屿数量+1。