P10638 BZOJ4355 Play with sequence

Maintain an integer sequence $a$ of length $n$, supporting three operations: - `1 u v c`: for $\forall i \in [u,v]$, change $a_i$ to $c$. - `2 u v c`: for $\forall i \in [u,v]$, change $a_i$ to $\max(a_i+c,0)$. - `3 u v`: output the value of $\sum \limits_{i=u}^v [a_i=0]$.

The first line contains two positive integers $n,m$, representing the sequence length and the number of operations. The second line contains $n$ integers $a_i$, representing the initial state of the sequence. Starting from the third line, the next $m$ lines each describe one operation.

Output several lines, one integer per line, answering each operation $3$ in order.

For $100\%$ of the testdata, $1\leq n,m\leq 3\times 10^5$, $0\leq a_i\leq 10^9$. - For operation $1$, it is guaranteed that $0\leq c\leq 10^9$. - For operation $2$, it is guaranteed that $|c| \leq 10^9$. For all operations, it is guaranteed that $1\leq u\leq v\leq n$. Translated by ChatGPT 5