Java program for fibonacci series for n elements

    package example;

import java.util.ArrayList;
import java.util.List;

public class Fibonacci {

public static void main(String[] args) {
int n =10;
int t1=0, t2=1;
int sum;

List<Integer> l = new ArrayList<>();
l.add(t1);l.add(t2);
for(int i = 1; i<(n - 1); i++)
{
  sum = t1 + t2;
  l.add(sum);
  t1 = t2;
  t2 = sum;

}
       System.out.println(l);
}

}

Output:  [0, 1, 1, 2, 3, 5, 8, 13, 21, 34]

Java program to count duplicates in a list

    package example;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

public class FruitsExample {


public static void main(String[] args) {

List<String> list = new ArrayList<String>();
        list.addAll(Arrays.asList("banana","apple","apple","mango","banana","orange"));
        Map<String, Integer> map = new HashMap<String, Integer>();
         
        Set<String> set = new HashSet<String>();
        set.addAll(list);
     
        for(String str:set)
        {
        int occ = Collections.frequency(list, str);
       
        map.put(str,occ);
        }
         
        System.out.println(map);
        map.forEach((k,n) -> System.out.println(k+"->"+n));
}
}

OUTPUT:  {banana=2, orange=1, apple=2, mango=1}
banana->2
orange->1
apple->2
mango->1

Sorting an array using single loop

 

            package example;

public class singleLoopSort {

public static void main(String[] args) {
int[] list = {23,90,45,78,56,45,23};
int temp;

for(int i = 0; i < list.length - 1; i++)
{
if (list[i] > list[i + 1]) {
temp = list[i];
list[i] = list[i + 1];
list[i + 1] = temp;
i = 0;
}
}

  for (int i = 0; i < list.length; i++) {
        System.out.print(list[i] + " ");
    }
 
  System.out.println("REVERSE ORDER :");
  for (int i = list.length -1 ; i >= 0; i--) {
        System.out.print(list[i] + " ");
    }  
}

}

output:
23 45 56 78 90
REVERSE ORDER : 90 78 56 45 23 

Java program using var args

package example;

public class varargs {

public static void main(String[] args) {
System.out.println("1:" + sum(1, 2, 3));
System.out.println("2:" + sum(1, 2, 3, 6, 7, 0));

}

public static int sum(int... a) {
int sum1 = 0;

for (int i : a) {
sum1 = sum1 + i;
}
return sum1;

}

}

Output: 

1:6

2:19

Java program to count number of palindrome words in a given sentence

package example;

import java.util.StringTokenizer;

public class palindromeCount {

public static void main(String[] args) {
String str = " Madam Arora non teaches io malayalam ";
StringTokenizer st = new StringTokenizer(str, " ");
int palinCount = 0;

while (st.hasMoreElements()) {
if (checkPalindrome(st.nextToken())) {
palinCount++;
}
}
System.out.println("palindrome words count:" + palinCount);

}

private static boolean checkPalindrome(String str) {
StringBuilder sb = new StringBuilder();
sb.append(str);
if (str.equalsIgnoreCase(sb.reverse().toString())) {
return true;
} else
return false;

}

}

Output:    palindrome words count:4