【leetcode】 859 Buddy Strings

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描述
这道题交换两个字符后相等

我的做法

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class Solution {
public:
    bool buddyStrings(string A, string B) {
        if (A.length() != B.length())//长度不同直接返回false
        {
            return false;
        }
        int strLength = A.length();
        if (A==B)//字符串一样直接返回true
        {
            //存在两个相同的字符才可以
            for (int i = 0; i < strLength; i++)
            {
                for (int j = i + 1; j < strLength; j++)
                {
                    if (A.at(i) == A.at(j))
                    {
                        return true;
                    }
                }
            }

            return false;
        }

        int ind1, ind2;//能成功的必须只有两处不同
        int flag = 0;
        for (int i = 0; i < strLength; i++)
        {
            if (A.at(i) != B.at(i))
            {
                flag++;
                if (flag == 1)
                {
                    ind1 = i;
                }
                else if (flag == 2)
                {
                    ind2 = i;
                }
                else
                {
                    return false;
                }
            }
        }
        int temp_val = A.at(ind1);
        A.at(ind1) = A.at(ind2);
        A.at(ind2) = temp_val;
        if (A == B)
        {
            return true;
        }
        else
        {
            return false;
        }
    }
};

大佬做法

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class Solution {
public:
    bool buddyStrings(string A, string B) {
        if (A.length() != B.length()) {
            return false;
        }
        if (A.length() < 2) {
            return false;
        }
        bool bRpeat = false;
        bool map[26] = {false};
        int diffCnt = 0;
        int ind[2];
        for (int i = 0; i < A.length(); i++)
        {
            if (map[A[i] - 'a']) { bRpeat = true; }
            map[A[i] - 'a'] = true;
            if (A[i] != B[i]) {
                if (diffCnt >= 2) { return false; }
                ind[diffCnt++] = i;
            }

        }
        if (diffCnt == 0 && bRpeat) { return true; }
        return A[ind[0]] == B[ind[1]] && A[ind[1]] == B[ind[0]];
    }
};

**参考资料*
[原题链接](https://leetcode.com/problems/buddy-strings/description/)