Cross The Streams is a binary determination puzzle in which the cells in a grid are split into either shaded or unshaded.
The objective is to shade some cells, subject to the following rules:
- All shaded cells must connect horizontally or vertically upon completion.
- No 2x2 area of shaded cells is allowed.
- Numbers to the left/top of the grid match with connected shaded cells in the respective row/column, in order. The length of these groups of connected shaded cells is equal to the value of the clue, separated by at least 1 unshaded cell.
- A question mark (?) represents a single clue whose value is unknown.
- An asterisk (*) represents any number of unknown clues, including none at all.
A standard 10x10 cross the streams and its solution.