The urban planning of Baidu's real problem (number of connected domains)

Topic:

A two-dimensional matrix is given, the matrix element is 1 or 0, and the number of independent non-connected regions consisting of 1 is calculated, and the bevel is 1 also connected. such as the following matrix:

0 1 0 0 0 0

0 1 0 1 0 0

0 0 0 0 1 1

The number of connected domains is 2.

Analysis:

Set up a collection list saves the coordinates that have been marked, loops through each point, marks the point with a value of 1, and marks the point adjacent to the point (using recursion, you can mark all points connected to that point).

The following code:

 Packageproject001;Importjava.util.ArrayList;Importjava.util.List; Public classMain09 {//find the number of 1 non-connected regions in the matrix, and diagonal is also connected     Public Staticlist<int[]> markedlist =Newarraylist<int[]>();  Public Static voidMain (string[] args) {int[] Maze = {{0,0,0,0,0},                        {0,1,0,0,0},                        {0,0,0,1,0},                        {1,1,0,0,0},                        {0,0,0,1,1}}; Doublet =System.currenttimemillis ();            System.out.println (Getl (FILLM (Maze))); }     Public Static intGetl (int[] M) {        intCount = 0; introw =m.length; intCol = m[0].length;  for(inti = 0;i<row;i++){             for(intj=0;j<col;j++){                //when the point is marked, and is 1 o'clock, all points connected to that point are marked                if(M[i][j]==1 &&!)ismarked (I,J))                    {Markpoint (i,j,m); Count++; }            }        }        returncount; }         Public Static int[] FILLM (int[] M) {        introw =m.length; intCol = m[0].length; int[] M2 =New int[Row+2] [Col+2];  for(inti = 1;i<=row;i++){             for(intj=1;j<=col;j++) {M2[i][j]=m[i-1][j-1]; }        }        returnM2; }        //determine if the point is marked     Public Static BooleanIsmarked (intIintj) {        intSize =markedlist.size (); if(size<=0)return false;  for(intk=0;k<size;k++){            int[] m =Markedlist.get (k); if(M[0]==I&AMP;&AMP;M[1]==J)return true; }        return false; }    //Mark Point (I,J) and mark all areas connected to that point     Public Static voidMarkpoint (intIintJint[] M) {        if(ismarked (I,J))return ; //mark the point, which is placed in a list        int[] m =New int[]{i,j};                Markedlist.add (m); //marks a point that is adjacent to a point (I,J) and is not marked        if(!ismarked (i-1,j-1) &&m[i-1][j-1]==1) Markpoint (i-1,j-1, M); if(!ismarked (I-1,J) &&m[i-1][j]==1) Markpoint (i-1, j,m); if(!ismarked (i-1,j+1) &&m[i-1][j+1]==1) Markpoint (i-1,j+1, M); if(!ismarked (i,j-1) &&m[i][j-1]==1) Markpoint (i,j-1, M); if(!ismarked (i,j+1) &&m[i][j+1]==1) Markpoint (i,j+1, M); if(!ismarked (i+1,j-1) &&m[i+1][j-1]==1) Markpoint (i+1,j-1, M); if(!ismarked (I+1,J) &&m[i+1][j]==1) Markpoint (i+1, j,m); if(!ismarked (i+1,j+1) &&m[i+1][j+1]==1) Markpoint (i+1,j+1, M); }    //Print Matrix     Public Static voidPRINTM (int[] m) {        introw =m.length; intCol = m[0].length;  for(inti=0;i<row;i++){             for(intj=0;j<col;j++) {System.out.print (M[i][j]+" "); } System.out.println (""); }    }}

The urban planning of Baidu's real problem (number of connected domains)