diff --git a/problems/0015.三数之和.md b/problems/0015.三数之和.md index adb9a113..6b5311ae 100644 --- a/problems/0015.三数之和.md +++ b/problems/0015.三数之和.md @@ -434,6 +434,46 @@ class Solution { } ``` +Swift: +```swift +// 双指针法 +func threeSum(_ nums: [Int]) -> [[Int]] { + var res = [[Int]]() + var sorted = nums + sorted.sort() + for i in 0 ..< sorted.count { + if sorted[i] > 0 { + return res + } + if i > 0 && sorted[i] == sorted[i - 1] { + continue + } + var left = i + 1 + var right = sorted.count - 1 + while left < right { + let sum = sorted[i] + sorted[left] + sorted[right] + if sum < 0 { + left += 1 + } else if sum > 0 { + right -= 1 + } else { + res.append([sorted[i], sorted[left], sorted[right]]) + + while left < right && sorted[left] == sorted[left + 1] { + left += 1 + } + while left < right && sorted[right] == sorted[right - 1] { + right -= 1 + } + + left += 1 + right -= 1 + } + } + } + return res +} +``` ----------------------- * 作者微信:[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)