一到n的乘积

#include <stdio.h>
  int main()
  {
      int n,j,sun=1;
      printf("input n:");
          scanf("%d",&n);

      for (j=1;j<=n;j++)
      {
          sun=sun*j;
       printf("j=%d\n",j);
      }
      printf("sun=%d\n",sun);
      return 0;

  }