剑指offer-矩阵中的路径

 1 class Solution {
 2 public:
 3     bool hasPath(char* matrix, int rows, int cols, char* str)
 4     {
 5         if(cols == 0 || str == nullptr || matrix == nullptr)
 6         {
 7             return false;
 8         }
 9         bool *vis = new bool[rows*cols];
10         memset(vis,0,rows*cols);
11         int pathLength = 0;
12         for(int row = 0;row < rows;++row)
13         {
14             for(int col = 0; col < cols;++col)
15             {
16                 if(dfs(matrix,rows,cols,row,col,str,pathLength,vis))
17                 {
18                     return true;
19                 }
20             }
21         }
22         delete[] vis;
23         return false;
24     }
25     bool dfs(char* matrix,int rows,int cols,int row,int col,char* str,int& pathLength,bool* vis)
26     {
27         if(str[pathLength] == ‘\0‘)
28         {
29             return true;
30         }
31         bool h = false;
32         if(row >= 0 && row < rows && col >= 0 && col < cols && matrix[row * cols + col] == str[pathLength] && !vis[row * cols + col])
33         {
34             ++pathLength;
35             vis[row*cols + col] = true;
36             h = dfs(matrix,rows,cols,row+1,col,str,pathLength,vis)
37                 ||dfs(matrix,rows,cols,row,col+1,str,pathLength,vis)
38                 ||dfs(matrix,rows,cols,row-1,col,str,pathLength,vis)
39                 ||dfs(matrix,rows,cols,row,col-1,str,pathLength,vis);
40             if(!h)
41             {
42                 --pathLength;
43                 vis[row*cols + col] = false;
44             }
45         }
46         return h;
47         
48     }
49     
50 
51 
52 };