它们被划分为整数运算.因此，将整数a除以整数b可得到b符合a的次数.同样，a % b将给您除法的余数.所以(a / b ) * b + a % b = a

They are being divided in integer arithmetics. So dividing integer a by integer b you get how many times b fits into a. Also a % b will give you a remainder of a division. So (a / b ) * b + a % b = a