Square matrix clockwise rotation of the implementation code

For example, the following square matrix:

  1   2   3   4
  5   6   7   8
  9 10 11 12

13 14 15 16

Clockwise rotation, but the following results:

13   9   5   1
10 of 14   6   2
15 11   7   3
16 12   8   4

#include <stdio.h>
void rotate(int* x, int rank)
{
 int* y = (int*)malloc(sizeof(int) * rank * rank);  
 for(int i=0; i<rank * rank; i++)
 {
         //Analysis with the original first line & NBSP; The number of rows becomes the same column & PI; Take the original first column and make it the same row. & have spent (I %rank)*rank turns a column into a row & cake; & have spent Rank -(I /rank)-1) makes the row a column
  y[(i%rank)*rank+(rank-(i/rank)-1) ] = x[i];  
 }
 for(i=0; i<rank*rank; i++)
 {
  x[i] = y[i];
 }
 free(y);
}
int main(int argc, char* argv[])
{
 int x[4][4] = {{1,2,3,4},{5,6,7,8},{9,10,11,12},{13,14,15,16}};
 int rank = 4;
 rotate(&x[0][0], rank);
 for(int i=0; i<rank; i++)
 {
  for(int j=0; j<rank; j++)
  {
   printf("%4d", x[i][j]);
  }
  printf("n");
 }
 return 0;
}