roundup
#define roundup(x, y) ((((x)+((y)-1))/(y))*(y))
#define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */ // 比x大,y的最小倍数
#define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */
#define roundup(x, y) ((((x) + ((y) -1)) / (y)) * (y)) /* to any y */
#define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */