Skip to main content

Longest Palindromic Substring

 Ex:- If the given string is "codedoh"

Output:-  "odedo" is the longest palindromic substring


Java


 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
 public String longestPalindrome(String s) {
    if (s == null || s.length() < 1) return "";
    int start = 0, end = 0;
    for (int i = 0; i < s.length(); i++) {
        int len1 = expandAroundCenter(s, i, i);
        int len2 = expandAroundCenter(s, i, i + 1);
        int len = Math.max(len1, len2);
        if (len > end - start) {
            start = i - (len - 1) / 2;
            end = i + len / 2;
        }
    }
    return s.substring(start, end + 1);
 }

 private int expandAroundCenter(String s, int left, int right) {
    int L = left, R = right;
    while (L >= 0 && R < s.length() && s.charAt(L) == s.charAt(R)) {
        L--;
        R++;
    }
    return R - L - 1;
 }

Popular posts from this blog

Check whether a number is Seed of another number

 A number P is said to be the seed of another number Q if multiplying P with its digits equates to Q. Ex:-  123 is seed of 738 as    123 * 1 * 2 * 3 = 738  Java 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 public class Seed{ public static void main (String[] args){ int num1 = 123 , num2 = 738 ; num1 = Math. min (num1,num2); num2 = Math. max (num1,num2); System. out . println (checkSeed(num1, num2)); } public static boolean checkSeed ( int num1, int num2){ int seed = num1; while (num1> 0 ){ seed = seed * (num1% 10 ); num1 = num1 / 10 ; } if (seed==num2) return true ; else return false ; } } Python def checkSeed(num1,num2): seed = num1 while num1 > 0 : seed = seed * (num1 % 10 ) num1 = num1 // 10 if seed == n
Read more

Program to sort the first half of an array in ascending and second half in descending order

Ex:-  [2, 4, 3, 10, 5, 8] [2, 4, 3]  and [10, 5, 8] ====>  [2, 3, 4] ascending                                                              [10, 8, 5] descending [ 2, 3, 4, 10, 8, 5] is the required answer.  Java 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 public class ArraySort{ public static void main (String[] args){ int [] arr = { 2 , 4 , 3 , 10 , 5 , 8 }; //sorting first half in ascending order for ( int i= 0 ; i<(arr. length / 2 ); i++){ for ( int j=i+ 1 ; j<(arr. length / 2 ); j++){ if (arr[i]>arr[j]){ int temp = arr[i]; arr[i] = arr[j]; arr[j] = temp; } } } //sorting second half in descending order for ( int i=(arr. length / 2 ); i<arr. length ; i++){ for ( int j=i+ 1 ; j<arr. length ; j++)
Read more

Write a method to move hyphens to the left and characters to the right in a string

 Ex:-     code--heist--   ==>     ----codeheist Note:-  Return null or None if str is empty. Java 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 public static String moveHyphens (String str) { if (str. length ()== 0 ) return null ; else { String result = "" ; for ( int i= 0 ; i<str. length (); i++){ char ch = str. charAt (i); if (ch== '-' ) result = ch + result; else result += ch; } return result; } } Python def moveHyphens (str): if len(str)== 0 : return None else : result = "" for char in str: if char== '-' : result = char + result; else : result += char return result
Read more