题目描述You are given $n$ integers $a_1, a_2, \ldots, a_n$ . Find the maximum value of $max(a_l, a_{l + 1}, \ldots, a_r) \cdot min(a_l, a_{l + 1}, \ldots, a_r)$ over all pairs $(l, r)$ of integers for ...
题目描述A string $s$ of length $n$ , consisting of lowercase letters of the English alphabet, is given.You must choose some number $k$ between $0$ and $n$ . Then, you select $k$characters of $s$ and pe...
题目描述The Olympic Games have just started and Federico is eager to watch the marathon race.There will be $n$ athletes, numbered from $1$ to $n$ , competing in the marathon, and all of them have taken...
题目描述A string $s$ of length $n$ ( $1 \le n \le 26$ ) is called alphabetical if it can be obtained using the following algorithm:first, write an empty string to $s$ (i.e. perform the assignment $s$ :...