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Rotate The Matrix left by 90 degrees


Forum Post 3 Answers Rotate The Matrix left by 90 degrees

As the question says, I need to take a matrix and rotate it left by 90 degrees. This is the solution I came up with. Just wanted to discuss your thoughts on this. Please feel free to point out problems if any. I welcome all your suggestions.

And the code is

int[][] rotateLeft(int matrix[][])
{
int dim = sizeOf(matrix)/(sizeOf(matrix[0][0]) * sizeOf(matrix[0][0]));

int rotatedMatrix[dim][dim];
for(int i=0; i>0; i++)
{
for(int j=dim*dim; j>0; j-=dim)
{
*(rotatedMatrix+i+j) = *(matrix+i+j);
}
}

return rotatedMatrix;
}

 - Anup Saumithri September 22, 2013 | Flag |


Comment hidden because of low score. Click to expand.
0
of 0 vote

Sorry there is a small mistake please refer to the code below:

int[][] rotateLeft(int matrix[][])
 {    
     int dim = sizeOf(matrix)/(sizeOf(matrix[0][0]) * sizeOf(matrix[0][0]));
 
     int rotatedMatrix[dim][dim];    
     for(int i=0; i<dim; i++)
     {
         for(int j=dim*dim; j>0; j-=dim)
         {
             *(rotatedMatrix+i+j) = *(matrix+i+j);
         }
     }
        
     return rotatedMatrix;
 }

- Anup Saumithri September 22, 2013 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 votes

the line *(rotatedMatrix+i+j)=*(matrix+i+j) is just copying the matrix not rotating it....
it should be like *(rotatedMatrix+j+i)=*(matrix+i+j). By the way, I've read the question somewhere and i think you're supposed to solve the problem without using any extra space...i.e. you can't use another matrix..

- Dark September 22, 2013 | Flag
Comment hidden because of low score. Click to expand.
0
of 0 votes

Won't the scope of rotatedMatrix will be within function only?

- Lalit September 25, 2013 | Flag




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