CF1927G Paint Charges

A horizontal grid strip of $ n $ cells is given. In the $ i $ -th cell, there is a paint charge of size $ a_i $ . This charge can be: - either used to the left — then all cells to the left at a distance less than $ a_i $ (from $ \max(i - a_i + 1, 1) $ to $ i $ inclusive) will be painted, - or used to the right — then all cells to the right at a distance less than $ a_i $ (from $ i $ to $ \min(i + a_i - 1, n) $ inclusive) will be painted, - or not used at all. Note that a charge can be used no more than once (that is, it cannot be used simultaneously to the left and to the right). It is allowed for a cell to be painted more than once. What is the minimum number of times a charge needs to be used to paint all the cells of the strip?

The first line of the input contains an integer $ t $ ( $ 1 \le t \le 100 $ ) — the number of test cases in the test. This is followed by descriptions of $ t $ test cases. Each test case is specified by two lines. The first one contains an integer $ n $ ( $ 1 \le n \le 100 $ ) — the number of cells in the strip. The second line contains $ n $ positive integers $ a_1, a_2, \dots, a_n $ ( $ 1 \le a_i \le n $ ), where $ a_i $ is the size of the paint charge in the $ i $ -th cell from the left of the strip. It is guaranteed that the sum of the values of $ n $ in the test does not exceed $ 1000 $ .

For each test case, output the minimum number of times the charges need to be used to paint all the cells of the strip.

In the third test case of the example, it is sufficient to use the charge from the $ 1 $ -st cell to the right, then it will cover both cells $ 1 $ and $ 2 $ . In the ninth test case of the example, you need to: - use the charge from the $ 3 $ -rd cell to the left, covering cells from the $ 1 $ -st to the $ 3 $ -rd; - use the charge from the $ 5 $ -th cell to the left, covering cells from the $ 4 $ -th to the $ 5 $ -th; - use the charge from the $ 7 $ -th cell to the left, covering cells from the $ 6 $ -th to the $ 7 $ -th. In the eleventh test case of the example, you need to: - use the charge from the $ 5 $ -th cell to the right, covering cells from the $ 5 $ -th to the $ 10 $ -th; - use the charge from the $ 7 $ -th cell to the left, covering cells from the $ 1 $ -st to the $ 7 $ -th.