中兴2016蓝剑之路挑战赛软件编程初赛赛题 计算房屋个数

题目描述：给定一个n*m的二维数组grid[n][m]，数组的值为0或1,1的地方代表一个房屋数量，左右或上下相邻认为是一个房屋数量，求共有多少个屋子？

分       析：首先遍历数组，计算数组中所有为1的个数，但如果这个1的（右边为1且下边为0）或（右边为0且下边为1）或（右方下方右下方均为1）时给房屋数量减1，若右方下方为1且右下方为0时减2，遍历完数组即可得出房屋数量

代      码：

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1. public class Test {  
2.     static int result = 0;  
3.     public static int pa(int grid[][]){  
4.         int m = grid.length;  
5.         int n = grid[0].length;  
6.         int x = m - 1;  
7.         int y = n - 1;  
8.         if (grid != null) {  
9.             for (int i = 0; i < m;i++) {  
10.                 for (int j = 0; j < n;j++) {  
11.                     if(grid[i][j] == 1){  
12.                         ++result;  
13.                         if (i == x && j < y) {  
14.                             if (grid[i][j+1] == 1) {  
15.                                 result -= 1;  
16.                             }  
17.                         }  
18.                         if (i < x && j == y) {  
19.                             if (grid[i+1][j] == 1) {  
20.                                 result -= 1;  
21.                             }  
22.                         }  
23.                         if (i < x && j < y) {  
24.                             if (grid[i][j+1] == 1 && grid[i+1][j] == 0) {  
25.                                 result = result - 1;  
26.                             }  
27.                             if (grid[i][j+1] == 0 && grid[i+1][j] == 1) {  
28.                                 result = result - 1;  
29.                             }  
30.                             if (grid[i][j+1] == 1 && grid[i+1][j] == 1 && grid[i+1][j+1] == 1) {  
31.                                 result = result - 1;  
32.                             }  
33.                             if (grid[i][j+1] == 1 && grid[i+1][j] == 1 && grid[i+1][j+1] == 0) {  
34.                                 result = result - 2;  
35.                             }  
36.                         }  
37.                     }  
38.                 }  
39.             }  
40.         }  
41.         return result;  
42.     }  
43.     public static void main(String[] args) {//      测试用例  
44. //      int[][]  a1 ={{1,1,0,0},{1,1,0,0},{0,0,1,1},{0,0,1,1}}; //2      
45. //      System.out.println(pa(a1));  
46. //      int[][]  a2 ={{0,0,0,0},{0,1,0,0},{0,0,1,0},{0,0,0,0}}; //2  
47. //      System.out.println(pa(a2));  
48. //      int[][]  a3 ={{1,1,0,0},{0,0,1,0},{0,1,0,0},{0,0,1,1}}; //4  
49. //      System.out.println(pa(a3));  
50. //      int[][]  a4 ={{1,1,0,0,1,1},{0,1,0,0,1,0},{1,0,1,1,0,1},{0,1,0,0,0,1}}; //6  
51. //      System.out.println(pa(a4));  
52. //      int[][]  a5 ={{1,1,0,0,0,0},{0,1,1,0,0,0},{0,0,1,1,0,0},{0,0,0,1,1,0},{0,0,0,0,1,1}}; //1  
53. //      System.out.println(pa(a5));  
54.         int[][]  a6 ={{1,1,0,1,0,1,1},{1,1,0,1,0,0,0},{1,1,1,0,0,1,0},{0,0,0,1,0,1,1},{1,1,0,0,0,1,0}}; //6  
55.         int s = pa(a6);  
56. }