C语言将24小时制转换为12小时制的方法

/*
* 24小时制转换为12小时制
*/
#include <stdio.h>
int main()
{
  int n,m;
  printf("Enter a 24-hour time:");
  scanf_s("%d:%d",&n,&m);
  if (n < 0)
  {
    printf("Error1!n");
    system("PAUSE");
    return 1;
  }
  else if (n < 12)
  {
    printf("Equivalent 12-hour time: %2d:%2d AMn",n,m);
  }
  else if ((n >= 12) && (n < 24))
  {
    n -= 12;
    printf("Equivalent 12-hour time: %2d:%2d PMn",m);
  }  
  else
  {
    printf("Error2!n");
    system("PAUSE");
    return 2;
  }
  system("PAUSE");
  return 0;
}