Spiral Matrix (Lintcode)

Spiral Matrix

Given a matrix of m x n elements (m rows, n columns), return all elements of the Matri X in Spiral Order.

Example

Given the following matrix:

[ [ 1, 2, 3 ], [ 4, 5, 6 ], [ 7, 8, 9 ]]

You should return [1,2,3,6,9,8,7,4,5] .

A rare time ac! Although the feeling is very water, but like this way of thinking clearly written down, there is no "small problem", and then submit, AC situation for me is still very few. Although the code is still a bit messy.

The idea is to define a two-dimensional array of directions, traversing in one Direction from (0,0), if a wall (the next traversal target crosses or has been traversed) continues to traverse in a direction that does not hit the wall, and ends when each direction hits a wall.

1  Public classSolution {2     /**3      * @parammatrix A matrix of M x n elements4      * @returnAn integer list5      */6      int[] f =New int[1000] [1000];7      PublicList<integer> Spiralorder (int[] matrix) {8list<integer> list =NewArraylist<integer>();9         intm =matrix.length;Ten         if(M = = 0)returnlist; One         intn = matrix[0].length; A          -         int[] D =New int[4] [2]; -D[0][0] = 0; D[0][1] = 1; theD[1][0] = 1; D[1][1] = 0; -D[2][0] = 0; D[2][1] = 1; -D[3][0] =-1; D[3][1] = 0; -          +         intcd = 0; -         inti = 0; +         intj = 0; AList.add (matrix[0][0]); atF[0][0] = 1; -         BooleanFlag =true; -          while(flag) { -             if(!IsV (i,j,d[cd],m,n)) { -                 intx = 0; -                  while(!ISV (I,j,d[cd],m,n) && x < 4) { incd = (CD + 1)% 4; -X + +; to                 } +                 if(x >= 4) flag =false; -}Else { thei + = D[cd][0]; *J + = D[cd][1]; $ List.add (Matrix[i][j]);Panax NotoginsengF[I][J] = 1; -             } the         } +          A         returnlist; the     } +      -     BooleanIsV (intIintJintD[],intMintN) { $         if(i + d[0] < 0 | | i + d[0] >= m)return false; $         if(j + d[1] < 0 | | j + d[1] >= N)return false; -         if(f[i + d[0]][j + d[1]]! = 0)return false; -         return true; the     } -}

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Spiral Matrix (Lintcode)