Given two strings A and B of lowercase letters, return true if and only if we can swap two letters in A so that the result equals B.
Example 1:
Input: A = "ab", B = "ba"
Output: true
Example 2:
Input: A = "ab", B = "ab"
Output: false
Example 3:
Input: A = "aa", B = "aa"
Output: true
Example 4:
Input: A = "aaaaaaabc", B = "aaaaaaacb"
Output: true
Example 5:
Input: A = "", B = "aa"
Output: false
题目大意：给出A,B两个字符串，问能否swap一次A串中的两个字符使得A==B
思路：直接找A中和B中不等的字符个数num，如果num==1，或者num==0且A串中有至少两个一样的字符那么就返回YES
代码写的有点乱...
class Solution {
public:
bool buddyStrings(string A, string B) {
string a = A;
string b = B;
sort(A.begin(), A.end());
sort(B.begin(), B.end());
if (A!=B) return false;
int num = 0;
map<char, char> mp;
map<char, int> cnt;
for (int i = 0; i < a.size(); ++i) {
if (a[i] != b[i] && mp[a[i]] != b[i]) {
num++;
mp[b[i]] = a[i];
}
cnt[a[i]]++;
}
if (num == 1) return true;
else if (num == 0) {
for (auto x : cnt){
//cout << x.first <<" " << x.second << endl;
if (x.second >= 2) return true;
}
//cout << "no" << endl;
return false;
}
return false;
}
};