Minimum Number of Increments on Subarrays to Form a Target Array
You are given an integer array target. You have an integer array initial of the same size as target with all elements initially zeros.
In one operation you can choose any subarray from initial and increment each value by one.
Return the minimum number of operations to form a target array from initial.
The test cases are generated so that the answer fits in a 32-bit integer.
Example 1
Input
target = [1,2,3,2,1]Output
3We need at least 3 operations: increment indices 0 to 4, then 1 to 3, then index 2 to form the target array.
Example 2
Input
target = [3,1,1,2]Output
4The target can be formed in 4 operations by incrementing suitable subarrays as shown.
Constraints
- 1 <= target.length <= 10^5
- 1 <= target[i] <= 10^5
- The input is generated such that the answer fits inside a 32 bit integer.