| # Coordinate Compression | |
| ## Description | |
| Replace each integer by its rank among the distinct input values while preserving equality and order. | |
| ## Input | |
| The verification-case input consists of an integer array `src` of length `n` and writable array `dest_map`. | |
| ## Output | |
| The function produces the number of distinct values and the sorted distinct-value map in `dest_map`. | |
| ## Constraints | |
| - All values and lengths fit in signed C `int` ranges. | |
| ## Source | |
| Classical algorithmic problem reconstructed from the verified C artifact. | |