Question

求满足a-b的绝对值＋ab=1的非负整数a、b的值？

快快快快快快快快快快快快快快快快快快快快看！！！！！！！！！！！！！！！！！！！！！！

Answer 1

|a-b| + ab = 1
a、b均为非负整数, 则
1. |a-b| = 0, ab =1, 可得a = b =1
2. |a-b| = 1, ab =0
a = 0, b =1 (b=-1舍去)
或 b = 0, a =1 (a=-1舍去)
所以有三组解：a = b = 1; a = 0, b = 1; a =1, b = 0