Match Two Strings with Exactly One Distinct-Index Swap
Company: Amazon
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: easy
Interview Round: Other
### Problem
Return whether swapping the characters at exactly two different indices of s can make it equal to goal. Even when the strings already match, a real distinct-index swap is required.
```cpp
class Solution {
public:
bool buddyStrings(string s, string goal);
};
```
### Examples
**Example 1:**
```text
s = "abcd", goal = "adcb"
Output: true
Explanation: Swap positions1 and3.
```
**Example 2:**
```text
s = "abc", goal = "abc"
Output: false
Explanation: Every distinct-index swap changes this string because its letters are unique.
```
### Constraints
- Both string lengths lie in [1,20000].
- All characters are lowercase English letters.
### Contract considerations
Use exactly one swap of distinct positions, not zero swaps.
```hint Read the boundary condition
What mismatches can one swap change?
```
### Boundary reminders
Use exactly one swap of distinct positions, not zero swaps.
Overview: Match Two Strings with Exactly One Distinct-Index Swap. Return whether swapping the characters at exactly two different indices of s can make it equal to goal.
