Liescrapers

Normal sudoku rules apply.

SKYSCRAPERS: Each purple shape is a building, and its height equals the sum of the digits in any cells it occupies.

YELLOW SIGNS: In each 3x3 block, two buildings display a yellow sign; one accurately indicates the height of its building, the other is lying.

ARROWS: A white arrow indicates the number of buildings it can see in a straight line in the indicated direction. If a building further from the arrow is shorter than (or the same height as) a nearer building, then it cannot be seen, so is not counted. All arrows are truthful.

RIVER: Road bridges separate the river into segments whose digits have the same total.