Maximum Profit in Job Scheduling

Question

## Problem

Given jobs with start, end, and profit, pick non-overlapping jobs maximizing total profit.

## Example
```
start=[1,2,3,3], end=[3,4,5,6], profit=[50,10,40,70] -> 120
```

## Constraints
- 1 ≤ n ≤ 5 × 10^4

## Approach
Sort by end, DP + binary search for the last compatible job.