Thread: exercice help

Compare this

Code:

for ( r = 0 ; r < 4 ; r++ )
  for ( c = 0 ; c < 4 ; c++ )
    printf("%d ", mat[r][c] );
  printf("\n");

With this

Code:

for ( r = 3 ; r >= 0 ; r-- )
  for ( c = 0 ; c < 4 ; c++ )
    printf("%d ", mat[r][c] );
  printf("\n");

Can you figure it out now, now that you know loops can go in either direction?

no i didnt , case u need to permute between array , nt just show it on the screen , i find this code but i didnt understand it but it work , its full with fuction and i still didnt study them , so can u explain it to me and give me a simple prog and thnx .

Code:

#include <stdio.h>
#include <stdlib.h>
 
void displayMatrix(unsigned int const *p, unsigned int row, unsigned int col);
void rotate(unsigned int *pS, unsigned int *pD, unsigned int row, unsigned int col);
 
int main()
{
    // declarations
    unsigned int image[][4] = {{1,2,3,4}, {5,6,7,8}, {9,10,11,12}};
    unsigned int *pSource;
    unsigned int *pDestination;
    unsigned int m, n;
 
    // setting initial values and memory allocation
    m = 3, n = 4, pSource = (unsigned int *)image;
    pDestination = (unsigned int *)malloc(sizeof(int)*m*n);
 
    // process each buffer
    displayMatrix(pSource, m, n);
 
    rotate(pSource, pDestination, m, n);
 
    displayMatrix(pDestination, n, m);
 
    free(pDestination);
 
    getchar();
    return 0;
}
 
void displayMatrix(unsigned int const *p, unsigned int r, unsigned int c)
{
    unsigned int row, col;
    printf("\n\n");
 
    for(row = 0; row < r; row++)
    {
        for(col = 0; col < c; col++)
        {
            printf("%d\t", *(p + row * c + col));
        }
        printf("\n");
    }
 
    printf("\n\n");
}
 
void rotate(unsigned int *pS, unsigned int *pD, unsigned int row, unsigned int col)
{
    unsigned int r, c;
    for(r = 0; r < row; r++)
    {
        for(c = 0; c < col; c++)
        {
            *(pD + c * row + (row - r - 1)) = *(pS + r * col + c);
        }
    }
}