CSES Increasing Array II - Problem Statement

You have $n$ numbers. You can change each to any value. The cost of changing $a_i$ to $x$ is $|x - a_i|$. Make the array non-decreasing with minimum total cost.

This is the classic Slope Trick problem. Naive DP: $dp[i][v]$ = min cost for first $i$ elements with $a_i = v$. With $V = 10^9$, you can't store all values. You'll track the function's shape through its slope-change points. The solution is similar to Sonya, but without the strictly-increasing transform.