Fewest Interval Increments to Build a Target Skyline

### Problem Start with an all-zero array the same length as target. One operation adds 1 to every entry of any chosen contiguous subarray. Return the minimum operations needed to reach target exactly. The source restricts inputs so that the answer fits a 32-bit integer. ```cpp class Solution { public: int minNumberOperations(vector<int>& target); }; ``` ### Examples **Example 1:** ```text Input: target = [2,1,3] Output: 4 Explanation: Increment the entire array once,the first entry once,and the last entry twice. At least2 layers must start at index0,and2 more must start at the rise from1 to3. ``` **Example 2:** ```text Input: target = [4,4] Output: 4 Explanation: Four whole-array increments attain the target,and each position needs four increments. ``` ### Constraints - target has length 1 to 100000. - `1 <= target[i] <= 100000`. - Inputs are generated so that the minimum answer fits a signed 32-bit integer. ### Contract considerations All source target entries are positive; no new lower bound or broader overflow domain is substituted. ```hint Read the boundary condition Check flat regions, rises, and drops while respecting contiguous-interval increments. Explain why the minimum is attainable under the stated answer bound. ``` ### Boundary reminders All source target entries are positive; no new lower bound or broader overflow domain is substituted.