Balance Difficulties

Suppose a contest has $N$ problems, with difficulties $A_1, A_2, ..., A_N$, and we have a parameter $X$. The contest is said to be balanced if and only if the following conditions hold : - $A_i \ge A_{i - 1}$ for all $2 \le i \le N$, i.e. the problems are sorted in difficulty order. - $A_i - A_{i - 1} \le X$ for all $2 \le i \le N$, i.e. the difficulties between $2$ adjacent problems differ by a