Japanese Sums
Background
The origin of this puzzle is not known. It is something of a cross between Nonograms and Sudoku.
Puzzle and Goal
An unsolved puzzle consists of a square grid. Along the top and left are numbered clues, resembling a blank Nonograms puzzle.
The goal is to place numbers in some cells, and paint others black, to satisfy the clues.
Rules
The solved grid must satisfy the following conditions:
The clues represent the total sum of the blocks in the corresponding rank. For instance, "3" could represent a cell with 3, or a block of 1 and 2 (in some order).
No number is repeated in any rank; however, not every number need appear in every rank.
Cells without numbers are painted black.
Other Names
Japanische Summen; Summensuche; Zahleneinbaurätsel
Playable Online