LeetCode-859. Intimate string

Here are two strings s and goal , As long as we can exchange s The two letters in get and goal Equal result , Just go back to  true ; Otherwise return to false .

The definition of exchanging letters is ： Take two subscripts i and j （ Subscript from 0 Start ） And meet i != j , Then exchange s[i] and s[j] The character at .

for example , stay "abcd" Exchange subscripts in 0 And subscripts 2 Elements of can generate "cbad" .
 

Example 1：

Input ：s = "ab", goal = "ba"
Output ：true
explain ： You can exchange s[0] = 'a' and s[1] = 'b' Generate "ba", here s and goal equal .
Example 2：

Input ：s = "ab", goal = "ab"
Output ：false
explain ： You can only exchange s[0] = 'a' and s[1] = 'b' Generate "ba", here s and goal It's not equal .
Example 3：

Input ：s = "aa", goal = "aa"
Output ：true
explain ： You can exchange s[0] = 'a' and s[1] = 'a' Generate "aa", here s and goal equal .
Example 4：

Input ：s = "aaaaaaabc", goal = "aaaaaaacb"
Output ：true
 

Tips ：

1 <= s.length, goal.length <= 2 * 104
s and goal It's made up of lowercase letters

#include <iostream>
#include <string>
#include <unordered_map>
using namespace std;
class Solution {
public:
	bool buddyStrings(string s, string goal) {

		int count = 0;
		unordered_map<char, int> hashMp1;
		unordered_map<char, int> hashMp2;
		bool isBigThanTwo = false;

		if (s.length() != goal.length()) {
			return false;
		}

		for (int i = 0; i < s.size(); i++) {
			if (hashMp1.count(s[i]) == 0) {
				hashMp1[s[i]] = 1;
			}
			else {
				hashMp1[s[i]]++;
			}
			if (hashMp2.count(goal[i]) == 0) {
				hashMp2[goal[i]] = 1;
			}
			else {
				hashMp2[goal[i]]++;
			}

			if (s[i] != goal[i]) {
				count++;
			}
		}

		unordered_map<char, int>::iterator it = hashMp1.begin();
		while (it != hashMp1.end()) {
			if (hashMp1[it->first] > 1) {
				isBigThanTwo = true;
			}

			if (hashMp1[it->first] != hashMp2[it->first]) {
				return false;
			}
			it++;
		}

		if (isBigThanTwo && s == goal) {
			return true;
		}

		if (count == 2) {
			return true;
		}

		return false;
	}

};

int main() {

	Solution* ps = new Solution();

	cout << ps->buddyStrings("ab", "ba");

	return 0;
}