-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathSolution.cs
More file actions
37 lines (33 loc) · 905 Bytes
/
Solution.cs
File metadata and controls
37 lines (33 loc) · 905 Bytes
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
public class Solution
{
public string ShortestPalindrome(string s)
{
if (s.Length <= 1)
return s;
string reverseStr = new(s.Reverse().ToArray());
string combineStr = s + "#" + reverseStr;
int[] kmp = KMP(combineStr);
int palindromeLength = kmp[combineStr.Length - 1];
string addStr = reverseStr[..(s.Length - palindromeLength)];
return addStr + s;
}
private int[] KMP(string s)
{
var prefixTable = new int[s.Length];
prefixTable[0] = 0;
for (int i = 1; i < s.Length; i++)
{
int j = prefixTable[i - 1];
while (j > 0 && s[i] != s[j])
{
j = prefixTable[j - 1];
}
if (s[i] == s[j])
{
j++;
}
prefixTable[i] = j;
}
return prefixTable;
}
}