Java实现-岛屿的个数

public class Solution {    /**     * @param grid a boolean 2D matrix     * @return an integer     */    public int numIslands(boolean[][] grids) {        // Write your code here        if(grids.length==0){return 0;}int [][]grid=new int[grids.length][grids[0].length];for(int i=0;i<grids.length;i++){for(int j=0;j<grids[0].length;j++){if(grids[i][j]){grid[i][j]=1;}else{grid[i][j]=0;}}}ArrayList<Point> list=new ArrayList<Point>();int count=0;        for(int i=0;i<grid.length;i++){        for(int j=0;j<grid[0].length;j++){        Point p=new Point(grid[i][j], 0,1);        if(grid[i][j]==1){        if(list.isEmpty()){        p.where=++count;        list.add(p);        }else{        if(i>0){        Point temp=list.get(list.size()-grid[0].length);        if(temp.where>0){        p.where=temp.where;        }        }        if(j>0){        Point temp=list.get(list.size()-1);        if(temp.where>0){        if(p.where>0){        if(p.where>temp.where){        for(int k=0;k<list.size();k++){        if(list.get(k).where==p.where){        list.get(k).where=temp.where;        }        }        count--;        p.where=temp.where;        }else if(p.where<temp.where){        for(int k=0;k<list.size();k++){        if(list.get(k).where==temp.where){        list.get(k).where=p.where;        }        }        p.where=p.where;        count--;        }else{        p.where=temp.where;        }        }else{        p.where=temp.where;        }        }        }        if(p.where>0){        list.add(p);//        System.out.println("***************"+i+" "+j+"   "+p.where);        }else{        p.where=++count;//        System.out.println("----------"+i+" "+j+"   "+p.where);        list.add(p);        }        }        }else{        list.add(p);        }        }        }return count;    }}class Point{int value;//值int where;//属于哪一个类0int visited;//是否访问过public Point(int value,int where,int visited){this.value=value;this.where=where;this.visited=visited;}public int getValue() {return value;}public void setValue(int value) {this.value = value;}public int getWhere() {return where;}public void setWhere(int where) {this.where = where;}public int getVisited() {return visited;}public void setVisited(int visited) {this.visited = visited;}}