As soon as he leaves his house, all the traffic lights turn green, starting their green-red-green cycle. He wishes to drive to Billy-Bob’s house (which is right at intersection $K$) as fast as possible.

Initially all lights are off, and after exactly m moves John would like to have the first v bulbs on and the rest off; otherwise he loses the game. There is only one restriction: he is not allowed to press the …

John has n light bulbs and a switchboard with n switches; each bulb can be either on or off, and pressing the i −th switch changes the state of bulb i from on to off, and viceversa. He is using them to play a …

Farmer John tries to keep the cows sharp by letting them play with intellectual toys. One of the larger toys is the lights in the barn. Each of the N (2 ≤ N ≤ 100,000) cow stalls conveniently numbered 1..N …

The lights in some of the rooms are on while others are off. You need to turn all the lights on. Clicking on a block will toggle the state. The only problem is that the other rooms which share an edge will also …

The goal is to turn on some of the lights, such that there is exactly one lit bulb in each row, and exactly one lit bulb in each column. Normally this would be an easy exercise, but this puzzle has an …

Your task is to assign the lights A, B, C to the cages so that: each snake will change its lighting, i.e. it will be moved to the cage illuminated differently from the cage it currently inhabits;