The app
Mostovi
Islands sit on a grid, each one printed with a number. The number says how many bridge-ends belong to that island, and the whole board is finished when every number is satisfied. Everything else in the game is the consequence of four short rules.
- Bridges run straight — horizontally or vertically, island to island. Nothing bends.
- Bridges never cross one another.
- At most two bridges join the same pair of islands.
- Each board has exactly one arrangement that satisfies every number.
The boards are built by hand rather than generated, a few dozen of them, which is why they get harder in a shape that feels deliberate. There is undo, there is reset, and there is a hint that is deliberately rationed. The app runs offline, needs no account, and carries no advertising. It speaks Slovenian and English.
A small piece of arithmetic
How many bridges are even worth thinking about
Here is a question that has nothing to do with solving anything: scatter islands on an empty grid at random, and count the pairs a bridge could ever connect. Not the pairs that should be connected — only the ones the straight-line rule permits at all.
Within a single row holding m islands, a bridge can only join neighbours: any further pair would have to pass through an island in between. So that row offers m − 1 candidates, and the same holds down every column. Add it up and the whole board offers 2k − R − C candidates, where k is the number of islands and R, C are the rows and columns that happen to be occupied. The expected number of occupied rows follows from a hypergeometric count, so the answer is closed-form rather than simulated.
On a sparse board — the kind worth playing — the navy bar towers over the gold one: choosing where the islands sit has far more freedom than choosing how to wire them up. Crowd the grid and the bars swap places, because every island suddenly has neighbours on all four sides. Either way the wiring space looks small enough to brute-force, and it isn't: deciding whether a Hashiwokakero board can be solved at all was proved NP-complete (Andersson, 2009). The hardness does not live in the per-pair count. It lives in the requirement that the finished bridges hold the whole board together, which no count of candidate pairs can see.
Not here: no board, no islands, no numbers from the app, no bridge drawn and nothing solved. This counts how much room the rules leave. Mostovi is where you find out which of it matters.
One clarification
About the word in the name
The company is called AK Invest, and that name belongs to its own line of business, which this page does not go into. What is on offer here is a puzzle app. Nothing in Mostovi and nothing on this page is a financial instrument, a share, a deposit, a brokerage service or guidance about money, and none of it should be read that way.
Reaching us
Correspondence
Questions about the app, bug reports, or anything to do with the data it keeps: most@fibagayrimenkul.store. The privacy policy for Mostovi is a separate page: Privacy Policy.