P3902 Increasing

Given numbers $A_1, A_2, \cdots, A_n$, modify the fewest elements (to real values) so that the sequence becomes strictly increasing. Note: The original statement mistakenly said to modify to integers; it has now been corrected to real numbers. The testdata ensures that the integer approach would also AC (it just cannot pass the sample).

The first line contains an integer $n$. The second line contains $n$ integers $A_1, A_2, \cdots, A_n$.

Output one integer, the minimum number of elements to modify.

- Constraints: - For 50% of the testdata, $N \le 10^3$. - For 100% of the testdata, $1 \le N \le 10^5$, $1 \le A_i \le 10^9$. Translated by ChatGPT 5