Error: do not know how to do: for each pair s[i] and s[j], if there are different, check if check(s, i + 1, j) or check(s, i, j - 1) is correct or not. It means we perform check twice.
Error:
do not know how to do: for each pair s[i] and s[j], if there are different, check if check(s, i + 1, j) or check(s, i, j - 1) is correct or not. It means we perform check twice.