diff --git a/problems/0376.摆动序列.md b/problems/0376.摆动序列.md index efb9c6b6..0199d83b 100644 --- a/problems/0376.摆动序列.md +++ b/problems/0376.摆动序列.md @@ -462,21 +462,43 @@ var wiggleMaxLength = function(nums) { ```Rust impl Solution { pub fn wiggle_max_length(nums: Vec) -> i32 { - let len = nums.len() as usize; - if len <= 1 { - return len as i32; + if nums.len() == 1 { + return 1; } - let mut preDiff = 0; - let mut curDiff = 0; - let mut result = 1; - for i in 0..len-1 { - curDiff = nums[i+1] - nums[i]; - if (preDiff <= 0 && curDiff > 0) || (preDiff >= 0 && curDiff < 0) { - result += 1; - preDiff = curDiff; + let mut res = 1; + let mut pre_diff = 0; + for i in 0..nums.len() - 1 { + let cur_diff = nums[i + 1] - nums[i]; + if (pre_diff <= 0 && cur_diff > 0) || (pre_diff >= 0 && cur_diff < 0) { + res += 1; + pre_diff = cur_diff; } } - result + res + } +} +``` + +**动态规划** + +```rust +impl Solution { + pub fn wiggle_max_length(nums: Vec) -> i32 { + if nums.len() == 1 { + return 1; + } + let (mut down, mut up) = (1, 1); + for i in 1..nums.len() { + // i - 1 为峰顶 + if nums[i] < nums[i - 1] { + down = down.max(up + 1); + } + // i - 1 为峰谷 + if nums[i] > nums[i - 1] { + up = up.max(down + 1); + } + } + down.max(up) } } ```