题目描述
给定两个由小写字母构成的字符串 A 和 B ,只要我们可以通过交换 A 中的两个字母得到与 B 相等的结果,就返回 true ;否则返回 false 。
示例 1:
输入: A = “ab”, B = “ba”
输出: true
示例 2:
输入: A = “ab”, B = “ab”
输出: false
示例 3:
输入: A = “aa”, B = “aa”
输出: true
示例 4:
输入: A = “aaaaaaabc”, B = “aaaaaaacb”
输出: true
示例 5:
输入: A = “”, B = “aa”
输出: false
提示:
0 <= A.length <= 20000
0 <= B.length <= 20000
A 和 B 仅由小写字母构成。
思路分析
- 如果长度不相等,返回False
- 用diff记录不同的个数,inx 记录不同值不同值对应的索引
代码示例
class Solution(object):
def buddyStrings(self, A, B):
"""
:type A: str
:type B: str
:rtype: bool
"""
if len(A) != len(B):
return False
diff = 0
inx = []
for i,a in enumerate(A):
if B[i] != a:
diff += 1
inx.append(i)
counter = dict()
if diff == 0:
for a in A:
if a in counter and counter[a]:
return True
else:
counter[a] = True
if diff != 2:
return False
return A[inx[0]] == B[inx[1]] and A[inx[1]] == B[inx[0]]