Tango Solver,
sun and moon, solved.

Field guide

How the Tango Solver works.

Tango is LinkedIn's daily sun-and-moon logic puzzle — a rebranded version of the classic binary puzzle known as Binairo or Takuzu. You fill a 6×6 grid with suns (☀) and moons (🌙) so that every row and column ends up with exactly three of each, no more than two of the same symbol ever sit next to each other, and any = or × clue between two cells is respected — = means the pair must match, × means they must differ.

Entering your puzzle

Click a cell to cycle it through sun, moon, and empty, and click the edge between two cells to add a matching = or × clue if your board shows one. Once your grid matches what you see in the app, hit Solve.

The algorithm: constraint propagation, then backtracking

Tango's three rules translate directly into deduction rules the solver applies repeatedly until nothing more can be inferred:

• No three in a row. If two adjacent cells in a line already match, the cell immediately beyond them must be the opposite symbol.
• Equal counts. Once a row or column already has three of one symbol, every remaining empty cell in that line must be the other symbol.
• Linked cells. An = clue copies a cell's confirmed symbol to its partner; a × clue copies the opposite symbol.

These three rules alone solve the vast majority of the grid through pure propagation, no guessing required. If propagation stalls before the board is full, the solver falls back to backtracking: it tries a symbol in the most-constrained remaining cell, re-runs propagation, and backtracks if a contradiction appears.

Worked example

Say row 3 already reads sun, sun, _, _, moon, moon. The “no three in a row” rule forces cell 3 to be a moon (it can't extend the sun-sun pair). That new moon, combined with the row already containing two moons, triggers the “equal counts” rule: the row already has its quota of moons once cell 3 is set, so every other empty cell in that row must be a sun. One deduction cascades into the next without any trial and error.

Tips for solving it yourself

• Scan for pairs first. Any two identical symbols touching in a line instantly tells you the symbol on either side.
• Count each line as you go. The moment a row or column hits three of one symbol, every remaining cell in it is decided.
• Resolve linked clues early. A single confirmed cell connected by = or × often unlocks a whole chain of neighboring deductions.

Disclaimer: This tool is an independent fan creation and is not affiliated with, authorized, or endorsed by LinkedIn Corporation. “Tango” is a trademark of its respective owner. Provided for practice and entertainment only.