How do you check palindrome?

Problem statement:
How do you check palindrome?

1. public class Palindrome {
2.     public static void main(String[] args) {
3.         String s = "madam";
4.         isPalindrome(s);
5.     }
6.     public static void isPalindrome(String s) {
7.         String rev = "";
8.         char c[] = s.toCharArray();
9.         for (int i = s.length() - 1; i >= 0; i--) {
10.             rev = rev + c[i];
11.         }
12.         if (s.equals(rev))
13.             System.out.println("Yes");
14.         else
15.             System.out.println("No");
16.     }
17. }

Output:

Yes
Mehod-II:

1. public class Palindrome {
2.     public static void main(String[] args) {
3.         String s = "madam";
4.         System.out.println(isPalindrome(s) ? "Yes" : "No");
5.     }
6.     public static boolean isPalindrome(String s) {
7.         int p = s.length() - 1;
8.         boolean flag = true;
9.         char c[] = s.toCharArray();
10.         for (int i = 0; i < s.length() / 2; i++) {
11.             if (c[i] != c[p]) {
12.                 flag = false;
13.                 break;
14.             }
15.             p--;
16.         }
17.         return flag;
18.     }
19. }

Output:

Yes

Java String Reverse

Problem statement:
A palindrome is a word, phrase, number, or other sequence of characters which reads the same backward or forward.
Given a string , print Yes if it is a palindrome, print No otherwise
Constraints:
A will consist at most 50 lower case english letters.
Sample Input:
madam
Sample Output:
Yes

1. public class Palindrome {
2.     public static void main(String[] args) {
3.         String s = "madam";
4.         System.out.println(isPalindrome(s) ? "Yes" : "No");
5.     }
6.     public static boolean isPalindrome(String s) {
7.         int p = s.length() - 1;
8.         boolean flag = true;
9.         for (int i = 0; i < s.length() / 2; i++) {
10.             if (s.charAt(i) != s.charAt(p)) {
11.                 flag = false;
12.                 break;
13.             }
14.             p--;
15.         }
16.         return flag;
17.     }
18. }

Output:
Yes
Method-II:

1. public class Palindrome {
2.     public static void main(String[] args) {
3.         String s = "madam";
4.         isPalindrome(s);
5.     }
6.     public static void isPalindrome(String s) {
7.         String rev = "";
8.         for (int i = s.length() - 1; i >= 0; i--) {
9.             rev = rev + s.charAt(i);
10.         }
11.         if (s.equals(rev))
12.             System.out.println("Yes");
13.         elset a Palindrome");
14.     }
15. }

Output: 

Yes

How do you find longest common substring ?

Problem statement:
Given two strings S1 & S2. Find the longest common substring between S1 & S2.

1. import java.util.ArrayList;
2. import java.util.List;
3. 
   
4. public class LongestCommonSubstring {
5.     public static void main(String[] args) {
6.         String S1 = "LCLC";
7.         String S2 = "CLCL";
8.         //String S3 = "abcdabccab";
9.         //String S4 = "bcdaccabaabc";
10.         List<String> com = commonSubstring(S1, S2);
11.         for (String s: com){
12.             System.out.println(s);
13.         }
14.     }
15.     public static List<String> commonSubstring(String s1, String s2) {
16.         Integer match[][] = new Integer[s1.length()][s2.length()];
17.         int len1 = s1.length();
18.         int len2 = s2.length();
19.         int max = Integer.MIN_VALUE;    // max length of the string
20.         ArrayList<String> result = null;    // result list
21.         for (int i = 0; i < len1; i++) {    // row iteration
22.             for (int j = 0; j < len2; j++) {  // column iteration
23.                 if (s1.charAt(i) == s2.charAt(j)) {
24.                     if (i == 0 || j == 0)
25.                         match[i][j] = 1;
26.                     else
27.                         match[i][j] = match[i - 1][j - 1] + 1;
28.                     // if you find a longer common substring re-initialize 
29. // the max count and update the result list
30.                     if (match[i][j] > max) {
31.                         max = match[i][j];
32.                         result = new ArrayList<String>();
33.                         // substring starts at i-max+1 & ends at i
34.                         result.add(s1.substring(i - max + 1, i + 1));
35.                     }
36.    // else if you find a common substring with the max length, 
37.   // store it in the list
38.                     else if (match[i][j] == max) {
39.                         result.add(s1.substring(i - max + 1, i + 1));
40.                     }
41.                 } else {
42.                     match[i][j] = 0;
43.                 }
44.             }
45.         }
46.         return result;
47.     }
48. }

Output:

LCL

CLC

How do you convert int to string using java?

Problem statement:
You are given an integer n, you have to convert it into a string.
If your code successfully converts n into a string s the code will print "Good job". Otherwise it will print "Wrong answer".
n can range between 100 to 100 inclusive.
Sample Input 0
100
Sample Output 0
Good job

public class ConvertIntToString {
    public static void main(String[] args) {
        int n = 100;
        //String s = String.valueOf(n);    // method - 1
        //String s = "" + n;                    // method - 2
        String s = Integer.toString(n);     // method - 3
        if (n == Integer.parseInt(s)) {
            System.out.println("Good Job");
        } else {
            System.out.println("Wrong Answer");
        }
    }
}

Output:

Good Job

Generate Parentheses

Problem statement:

Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.

For example, given n = 3, a solution set is:

[

  "((()))",

  "(()())",

  "(())()",

  "()(())",

  "()()()"

]