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try-catch modularity

0 likes • Jan 31, 2023 • 0 views
Java
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LeetCode #21: Merge Two Sorted Lists

0 likes • Oct 15, 2022 • 0 views
Java
public class Solution {
public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
ListNode head = new ListNode(0);
ListNode handler = head;
while(l1 != null && l2 != null) {
if (l1.val <= l2.val) {
handler.next = l1;
l1 = l1.next;
} else {
handler.next = l2;
l2 = l2.next;
}
handler = handler.next;
}
if (l1 != null) {
handler.next = l1;
} else if (l2 != null) {
handler.next = l2;
}
return head.next;
}
}

Heap sort

0 likes • Nov 19, 2022 • 0 views
Java
import java.util.*;
public class HeapSortMain {
public static void buildheap(int []arr) {
/*
* As last non leaf node will be at (arr.length-1)/2
* so we will start from this location for heapifying the elements
* */
for(int i=(arr.length-1)/2; i>=0; i--){
heapify(arr,i,arr.length-1);
}
}
public static void heapify(int[] arr, int i,int size) {
int left = 2*i+1;
int right = 2*i+2;
int max;
if(left <= size && arr[left] > arr[i]){
max=left;
} else {
max=i;
}
if(right <= size && arr[right] > arr[max]) {
max=right;
}
// If max is not current node, exchange it with max of left and right child
if(max!=i) {
exchange(arr,i, max);
heapify(arr, max,size);
}
}
public static void exchange(int[] arr,int i, int j) {
int t = arr[i];
arr[i] = arr[j];
arr[j] = t;
}
public static int[] heapSort(int[] arr) {
buildheap(arr);
int sizeOfHeap=arr.length-1;
for(int i=sizeOfHeap; i>0; i--) {
exchange(arr,0, i);
sizeOfHeap=sizeOfHeap-1;
heapify(arr, 0,sizeOfHeap);
}
return arr;
}
public static void main(String[] args) {
int[] arr={1,10,16,19,3,5};
System.out.println("Before Heap Sort : ");
System.out.println(Arrays.toString(arr));
arr=heapSort(arr);
System.out.println("=====================");
System.out.println("After Heap Sort : ");
System.out.println(Arrays.toString(arr));
}
}

Factorial

0 likes • Nov 19, 2022 • 0 views
Java
public class Factorial
{
public static void main(String[] args)
{ final int NUM_FACTS = 100;
for(int i = 0; i < NUM_FACTS; i++)
System.out.println( i + "! is " + factorial(i));
}
public static int factorial(int n)
{ int result = 1;
for(int i = 2; i <= n; i++)
result *= i;
return result;
}
}

Word Counter

0 likes • Nov 19, 2022 • 0 views
Java
import java.io.File;
import java.io.IOException;
import java.util.Map;
import java.util.Scanner;
import java.util.TreeMap;
public class SimpleWordCounter {
public static void main(String[] args) {
try {
File f = new File("ciaFactBook2008.txt");
Scanner sc;
sc = new Scanner(f);
// sc.useDelimiter("[^a-zA-Z']+");
Map<String, Integer> wordCount = new TreeMap<String, Integer>();
while(sc.hasNext()) {
String word = sc.next();
if(!wordCount.containsKey(word))
wordCount.put(word, 1);
else
wordCount.put(word, wordCount.get(word) + 1);
}
// show results
for(String word : wordCount.keySet())
System.out.println(word + " " + wordCount.get(word));
System.out.println(wordCount.size());
}
catch(IOException e) {
System.out.println("Unable to read from file.");
}
}
}

Random Integers -> file

0 likes • Nov 19, 2022 • 0 views
Java
//sample code to write 100 random ints to a file, 1 per line
import java.io.PrintStream;
import java.io.IOException;
import java.io.File;
import java.util.Random;
public class WriteToFile {
public static void main(String[] args) {
try {
PrintStream writer = new PrintStream(new File("randInts.txt"));
Random r = new Random();
final int LIMIT = 100;
for (int i = 0; i < LIMIT; i++) {
writer.println(r.nextInt());
}
writer.close();
} catch (IOException e) {
System.out.println("An error occured while trying to write to the file");
}
}
}

quick sort

0 likes • Nov 19, 2022 • 0 views
Java
import java.util.Arrays;
public class QuickSortMain {
private static int array[];
public static void sort(int[] arr) {
if (arr == null || arr.length == 0) {
return;
}
array = arr;
quickSort(0, array.length-1);
}
private static void quickSort(int left, int right) {
int i = left;
int j = right;
// find pivot number, we will take it as mid
int pivot = array[left+(right-left)/2];
while (i <= j) {
/**
* In each iteration, we will increment left until we find element greater than pivot
* We will decrement right until we find element less than pivot
*/
while (array[i] < pivot) { i++; } while (array[j] > pivot) {
j--;
}
if (i <= j) {
exchange(i, j);
//move index to next position on both sides
i++;
j--;
}
}
// call quickSort() method recursively
if (left < j)
quickSort(left, j);
if (i < right)
quickSort(i, right);
}
private static void exchange(int i, int j) {
int temp = array[i];
array[i] = array[j];
array[j] = temp;
}
public static void main(String a[]){
int[] input = {33,21,45,64,55,34,11,8,3,5,1};
System.out.println("Before Sorting : ");
System.out.println(Arrays.toString(input));
sort(input);
System.out.println("==================");
System.out.println("After Sorting : ");
System.out.println(Arrays.toString(array));
}
}