diff options
| -rw-r--r-- | src/main.rs | 36 |
1 files changed, 27 insertions, 9 deletions
diff --git a/src/main.rs b/src/main.rs index d9ee527..4aa697a 100644 --- a/src/main.rs +++ b/src/main.rs @@ -309,12 +309,12 @@ mod tests { #[test] fn test_from_str() { - let p = Position::from("012"); + let p = Position::from("123"); assert_eq!(p.at(0, 0), Cell::OtherPlayer, "\n{:?}", p); assert_eq!(p.at(0, 1), Cell::CurrentPlayer, "\n{:?}", p); assert_eq!(p.at(0, 2), Cell::OtherPlayer, "\n{:?}", p); - let p = Position::from("000"); + let p = Position::from("111"); assert_eq!(p.at(0, 0), Cell::OtherPlayer, "\n{:?}", p); assert_eq!(p.at(1, 0), Cell::CurrentPlayer, "\n{:?}", p); assert_eq!(p.at(2, 0), Cell::OtherPlayer, "\n{:?}", p); @@ -325,7 +325,7 @@ mod tests { } } -fn solve(p: Position) -> i32 { +fn solve(p: Position, a: i32, b: i32) -> i32 { if p.is_draw() { return 0; } @@ -334,17 +334,35 @@ fn solve(p: Position) -> i32 { return (((WIDTH * HEIGHT + 1) as i32) - (p.play_count as i32)) / 2; } } - let mut best = -((WIDTH * HEIGHT) as i32); + + let mut alpha = a; + let mut beta = b; + + let max = (((WIDTH * HEIGHT + 1) as i32) - (p.play_count as i32)) / 2; + + if beta > max { + beta = max; + if (alpha >= beta) { + return beta; + } + } + for x in 0..WIDTH { if !p.is_valid_play(x) { continue } - let score = -solve(p.play(x)); - if score > best { - best = score; + + let score = -solve(p.play(x), -beta, -alpha); + + if (score >= beta) { + return score; + } + + if score > alpha { + alpha = score; } } - return best; + return alpha; } fn main() { @@ -354,5 +372,5 @@ fn main() { // p = p.play(1); // p = p.play(5); // println!("{:?}", p); - println!("{}", solve(p.clone())); + println!("{}", solve(p.clone(), -10000, 100000)); } |