[剑指Offer] 66.机器人的运动范围

 1 class Solution {
 2 public:
 3     int flag[1000][1000];
 4     int sum(int x,int y){
 5         int sum = 0;
 6         while(x > 0){
 7             sum += x % 10;
 8             x /= 10;
 9         }
10         while(y > 0){
11             sum += y % 10;
12             y /= 10;
13         }
14         return sum;
15     }
16     int dfs(int threshold, int rows, int cols, int i, int j){
17         int count = 0;
18         if(i >= 0 && i < rows && j >= 0 && j < cols && sum(i,j) <= threshold && flag[i][j] == 0){
19             flag[i][j] = 1;
20             count += dfs(threshold, rows, cols, i - 1, j)
21                      + dfs(threshold, rows, cols, i + 1, j)
22                      + dfs(threshold, rows, cols, i, j - 1)
23                      + dfs(threshold, rows, cols, i, j + 1)
24                      + 1;
25         }
26         return count;
27     }
28     int movingCount(int threshold, int rows, int cols)
29     {
30         memset(flag,0,sizeof(flag));
31         return dfs(threshold, rows, cols, 0, 0);
32     }
33 };