摘要： 题意：一串0，1代码，5中操作：0 a b change all characters into '0's in [a , b]1 a b change all characters into '1's in [a , b]2 a b change all '0's into '1's and change all '1's into '0's in [a, b]Output operations:3 a b output the number of '1's in [a, b]4 阅读全文