A15202 | $Mark the Dust Sweeper$

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题目描述

Mark is cleaning a row of $n$ rooms. The $i$ -th room has a nonnegative dust level $a_i$ . He has a magical cleaning machine that can do the following three-step operation. - Select two indices $i<j$ such that the dust levels $a_i$ , $a_{i+1}$ , $\dots$ , $a_{j-1}$ are all strictly greater than $0$ . - Set $a_i$ to $a_i-1$ . - Set $a_j$ to $a_j+1$ . Mark's goal is to make $a_1 = a_2 = \ldots = a_{n-1} = 0$ so that he can nicely sweep the $n$ -th room. Determine the minimum number of operations needed to reach his goal.

The first line contains a single integer $t$ ( $1\leq t\leq 10^4$ ) — the number of test cases. The first line of each test case contains a single integer $n$ ( $2\leq n\leq 2\cdot 10^5$ ) — the number of rooms. The second line of each test case contains $n$ integers $a_1$ , $a_2$ , ..., $a_n$ ( $0\leq a_i\leq 10^9$ ) — the dust level of each room. It is guaranteed that the sum of $n$ across all test cases does not exceed $2\cdot 10^5$ .

For each test case, print a line containing a single integer — the minimum number of operations. It can be proven that there is a sequence of operations that meets the goal.

输入 #1

4
3
2 0 0
5
0 2 0 2 0
6
2 0 3 0 4 6
4
0 0 0 10

输出 #1

C++ 编辑器

输入

输出