1790_仅执行一次字符串交换能否使两个字符串相等

类型：字符串

仅执行一次字符串交换能否使两个字符串相等 💚

https://leetcode-cn.com/problems/check-if-one-string-swap-can-make-strings-equal/

❓ 给你两个长度相等的字符串，如果对其中一个字符串执行最多一次字符交换（交换字符串中两个字符的位置）就可以使两个字符串相等，返回 true ；否则，返回 false 。

💡 一次遍历

使用两个指针，同步遍历这两个字符串。如果符合要求的话，应该会正好找到两处错位。

class Solution:
    def areAlmostEqual(self, s1: str, s2: str) -> bool:
        firstDiff = []
        secondDiff = []
        for i in range(len(s1)):
            diff = ord(s1[i]) - ord(s2[i])
            if diff == 0:
                continue
            if not firstDiff:
                firstDiff = [s1[i], s2[i]]
            elif not secondDiff:
                secondDiff = [s1[i], s2[i]]
            else:
                return False
        if firstDiff and not secondDiff:
            return False
        if not firstDiff and not secondDiff:
            return True
        return firstDiff[0] == secondDiff[1] and firstDiff[1] == secondDiff[0]

时间复杂度：O(n)，空间复杂度：O(1)