If there is one distinct character, check if the rest of string matches.

```
if s == t or abs(len(s) - len(t)) > 1: return False
for i in range(min(len(s), len(t))):
if s[i] != t[i]:
return s[:i]+s[i+1:] == t[:i]+t[i+1:] or s[:i]+s[i+1:] == t or t[:i]+t[i+1:] == s
return True
```