Your goal for this challenge is to implement Connect 4 in TypeScript types.
Each cell in the game can contain 🔴 or 🟡 or be empty ( ). You're provided with a rough layout of how to organize the board in the EmptyBoard type. The game state is represented by an object with a board property and a state property (which keeps track of which player is next up to play).
In case you haven't played it before: Connect 4 is a game in which the players choose a color and then take turns dropping colored tokens into a six-row, seven-column vertically suspended grid. The pieces fall straight down, occupying the lowest available space within the column. The objective of the game is to be the first to form a horizontal, vertical, or diagonal line of four of one's own tokens.
fun fact: Connect 4 is also known as Connect Four, Four Up, Plot Four, Find Four, Captain's Mistress, Four in a Row, Drop Four, and Gravitrips in the Soviet Union
another fun fact: Connect 4 was "solved" by James Allen and Victor Allis (independently from one another.. like two weeks apart!) in 1988. They couldn't do a full brute-force proof at the time, but 7 years later John Tromp in the Netherlands did it with a database on a Sun Microsystems and Silicon Graphics International workstations (for a combined total of 40,000 computation hours!).
type Move01 = Connect4<NewGame, 0>
/*
{
board: [
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
['🟡', ' ', ' ', ' ', ' ', ' ', ' '],
]
state: '🔴'
}
*/
type Move02 = Connect4<Move01, 0>
/*
{
board: [
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
['🔴', ' ', ' ', ' ', ' ', ' ', ' '],
['🟡', ' ', ' ', ' ', ' ', ' ', ' '],
]
state: '🟡'
}
*/
type Move03 = Connect4<Move02, 0>
/*
{
board: [
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
['🟡', ' ', ' ', ' ', ' ', ' ', ' '],
['🔴', ' ', ' ', ' ', ' ', ' ', ' '],
['🟡', ' ', ' ', ' ', ' ', ' ', ' '],
]
state: '🔴'
}
*/
type Move04 = Connect4<Move03, 1>
/*
{
board: [
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
['🟡', ' ', ' ', ' ', ' ', ' ', ' '],
['🔴', ' ', ' ', ' ', ' ', ' ', ' '],
['🟡', '🔴', ' ', ' ', ' ', ' ', ' '],
]
state: '🟡'
}
*/
type Move05 = Connect4<Move04, 2>
/*
{
board: [
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
['🟡', ' ', ' ', ' ', ' ', ' ', ' '],
['🔴', ' ', ' ', ' ', ' ', ' ', ' '],
['🟡', '🔴', '🟡', ' ', ' ', ' ', ' '],
]
state: '🔴'
}
*/
type Move06 = Connect4<Move05, 1>
/*
{
board: [
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
['🟡', ' ', ' ', ' ', ' ', ' ', ' '],
['🔴', '🔴', ' ', ' ', ' ', ' ', ' '],
['🟡', '🔴', '🟡', ' ', ' ', ' ', ' '],
]
state: '🟡'
}
*/
type RedWin = Connect4<
{
board: [
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
['🟡', ' ', ' ', ' ', ' ', ' ', ' '],
['🟡', ' ', ' ', ' ', ' ', ' ', ' '],
['🔴', '🔴', '🔴', ' ', ' ', ' ', ' '],
['🟡', '🔴', '🟡', '🟡', ' ', ' ', ' '],
]
state: '🔴'
},
3
>
/*
{
board: [
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
['🟡', ' ', ' ', ' ', ' ', ' ', ' '],
['🟡', ' ', ' ', ' ', ' ', ' ', ' '],
['🔴', '🔴', '🔴', '🔴', ' ', ' ', ' '],
['🟡', '🔴', '🟡', '🟡', ' ', ' ', ' '],
]
state: '🔴 Won'
}
*/
type YellowWin = Connect4<
{
board: [
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
['🔴', ' ', ' ', ' ', ' ', ' ', ' '],
['🟡', ' ', ' ', ' ', ' ', ' ', ' '],
['🔴', ' ', '🔴', '🔴', ' ', ' ', ' '],
['🟡', ' ', '🟡', '🟡', ' ', ' ', ' '],
]
state: '🟡'
},
1
>
/*
{
board: [
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
['🔴', ' ', ' ', ' ', ' ', ' ', ' '],
['🟡', ' ', ' ', ' ', ' ', ' ', ' '],
['🔴', ' ', '🔴', '🔴', ' ', ' ', ' '],
['🟡', '🟡', '🟡', '🟡', ' ', ' ', ' '],
]
state: '🟡 Won'
}
*/
type YellowDiagonalWin = Connect4<
{
board: [
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', '🟡', '🔴', ' ', ' ', ' '],
['🔴', '🟡', '🔴', '🔴', ' ', ' ', ' '],
['🟡', '🔴', '🟡', '🟡', ' ', ' ', ' '],
]
state: '🟡'
},
3
>
/*
{
board: [
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', ' ', ' ', ' ', ' '],
[' ', ' ', ' ', '🟡', ' ', ' ', ' '],
[' ', ' ', '🟡', '🔴', ' ', ' ', ' '],
['🔴', '🟡', '🔴', '🔴', ' ', ' ', ' '],
['🟡', '🔴', '🟡', '🟡', ' ', ' ', ' '],
]
state: '🟡 Won'
}
*/
type Draw = Connect4<
{
board: [
['🟡', '🔴', '🔴', '🟡', '🟡', '🔴', ' '],
['🔴', '🟡', '🟡', '🔴', '🔴', '🟡', '🔴'],
['🟡', '🔴', '🔴', '🟡', '🟡', '🔴', '🟡'],
['🔴', '🟡', '🟡', '🔴', '🔴', '🟡', '🔴'],
['🟡', '🔴', '🔴', '🟡', '🟡', '🔴', '🟡'],
['🔴', '🟡', '🟡', '🔴', '🔴', '🟡', '🔴'],
]
state: '🟡'
},
6
>
/*
{
board: [
['🟡', '🔴', '🔴', '🟡', '🟡', '🔴', '🟡'],
['🔴', '🟡', '🟡', '🔴', '🔴', '🟡', '🔴'],
['🟡', '🔴', '🔴', '🟡', '🟡', '🔴', '🟡'],
['🔴', '🟡', '🟡', '🔴', '🔴', '🟡', '🔴'],
['🟡', '🔴', '🔴', '🟡', '🟡', '🔴', '🟡'],
['🔴', '🟡', '🟡', '🔴', '🔴', '🟡', '🔴'],
]
state: 'Draw'
}
*/Prompt by Dimitri Mitropoulos of MiTS