Return the minimum number of characters you must insert anywhere into s to make it a palindrome. For example…

Question

Return the minimum number of characters you must insert anywhere into s to make it a palindrome. For example "mbadm" needs 2 insertions (one valid result is "mdbabdm"), while "zzazz" is already a palindrome and needs 0. The empty string and single characters need 0. Strings can be up to ~1000 characters; an O(n^2) DP is expected.

Prep Room · Answer

### Intuition To make a string into a palindrome with the minimum number of insertions, we need to find the longest symmetric part of the string that already…

Minimum insertions for palindrome