diff --git a/problems/0188.买卖股票的最佳时机IV.md b/problems/0188.买卖股票的最佳时机IV.md index 14f514a9..773a910a 100644 --- a/problems/0188.买卖股票的最佳时机IV.md +++ b/problems/0188.买卖股票的最佳时机IV.md @@ -474,6 +474,55 @@ function maxProfit(k: number, prices: number[]): number { }; ``` +Rust: + +```rust +impl Solution { + pub fn max_profit(k: i32, prices: Vec) -> i32 { + let mut dp = vec![vec![0; 2 * k as usize + 1]; prices.len()]; + + for v in dp[0].iter_mut().skip(1).step_by(2) { + *v = -prices[0]; + } + + for (i, &p) in prices.iter().enumerate().skip(1) { + for j in (0..2 * k as usize - 1).step_by(2) { + dp[i][j + 1] = dp[i - 1][j + 1].max(dp[i - 1][j] - p); + dp[i][j + 2] = dp[i - 1][j + 2].max(dp[i - 1][j + 1] + p); + } + } + + dp[prices.len() - 1][2 * k as usize] + } +} +``` + +空间优化: + +```rust +impl Solution { + pub fn max_profit(k: i32, prices: Vec) -> i32 { + let mut dp = vec![0; 2 * k as usize + 1]; + for v in dp.iter_mut().skip(1).step_by(2) { + *v = -prices[0]; + } + + for p in prices { + for i in 1..=2 * k as usize { + if i % 2 == 1 { + // 买入 + dp[i] = dp[i].max(dp[i - 1] - p); + continue; + } + // 卖出 + dp[i] = dp[i].max(dp[i - 1] + p); + } + } + + dp[2 * k as usize] + } +} +```