You have an array a consisting of n positive integers and you have to handle q queries of the following types: 1 i x: change ai to x, 2 l r k: check if the number of occurrences of every positive integer in the subarray al,al+1,…ar is a multiple of k (check the example for better understanding).

想到了一个随机的做法。没交上去。想交互题的 $Hard Version$ 浪费了太多时间。感觉用 $K$ 棵树状数组，然后每棵树都用不同的随机去做应该是对的