My Code Book

8/7/2019 My Code Book

http://slidepdf.com/reader/full/my-code-book 1/23

My Code Book Ramesh Perumalsamy

public static Object MYCodeBook;

A collection of the code and the experiments galore.

Also a supplement to the online content @

http://bestsourced.wordpress.com/



Merge Sort20 April 2011

Source code:

/**

* @author Ramesh

*/

public class MergeSort {

public static int ARRAYLEN = 10;

private static int MAX = 32768; // Sentinel

public static void main(String[] args) {

MergeSort mSort = new MergeSort();

// Creation and population of the Input array

Integer[] lstInt = new Integer[ARRAYLEN ];for (int i = 0; i < ARRAYLEN ; i++) {

lstInt[i] = ((int) (Math.random() * 100)); //Range : 0 - 99

}

System.out.print("Before : ");

mSort.printArray(lstInt);

mSort.mergeSort(lstInt, 0, ARRAYLEN - 1);

System.out.println("");

System.out.print("After : ");

mSort.printArray(lstInt);

}

// Merge Sort function - Recursive implementation

public void mergeSort(Integer[] lst, int p, int r) {

int q = 0;

if (p < r) {

q = (p + r) / 2;

mergeSort(lst, p, q);

mergeSort(lst, q + 1, r);

mergeProc(lst, p, q, r);

}

return;

}

// Merging Procedure - Merge into a single sorted array

public void mergeProc(Integer[] lst, int p, int q, int r) {

int n1, n2, i = 0, j = 0, k = 0;n1 = q - p + 1;

n2 = r - q;

Integer[] L = new Integer[n1 + 1]; // Left array

Integer[] R = new Integer[n2 + 1]; // Right array

for (i = 0; i < n1; i++) {

L[i] = lst[i + p];

}

for (j = 0; j < n2; j++) {

R[j] = lst[j + q + 1];



}

R[j] = MAX ; // Sentinel Values

L[i] = MAX ; // Sentinel Values

k = i = j = 0;

for (k = p; k <= r; k++) {

if (L[i] <= R[j]) { // Compare the first element of

lst[k] = L[i]; // Left and Right arrays

i++; // and populate the least value

} else { // Increment the appropriate pointer

lst[k] = R[j];

j++;

}

}

return;

}

public void mergeProcNoSentinel(Integer[] lst, int p, int q, int r) {

int n1, n2, i = 0, j = 0, k = 0;

n1 = q - p + 1;

n2 = r - q;

Integer[] L = new Integer[n1]; // Left array Integer[] R = new Integer[n2]; // Right array

for (i = 0; i < n1; i++) {

L[i] = lst[i + p];

}

for (j = 0; j < n2; j++) {

R[j] = lst[j + q + 1];

}

// R[j] = MAX; // NO Sentinel Values

// L[i] = MAX; // NO Sentinel Values

k = i = j = 0;

for (k = p; k <= r; k++) {

if (j >= n2 || ((i < n1) && (L[i] <= R[j]))) {

lst[k] = L[i];

i++;

} else {

lst[k] = R[j];

j++;

}

}

return;

}

// Array printing function - Generic

public <T> void printArray(T[] a) {

for (T t : a) {

System.out.print(t + " ");

}return;

}

}

Sample Output:Before : 32 19 80 17 64 17 38 84 69 49

After : 17 17 19 32 38 49 64 69 80 84



Insertion Sort & Binary Search21 April 2011

Source code:

/* @author rparumal

*

*/

public class InsertionSort {

/**

* @param args

*/

private static int ARRAYLEN = 10;


// TODO Auto-generated method stub

InsertionSort inSort = new InsertionSort();

Integer[] lstInt = new Integer[ARRAYLEN ];

for (int i = 0; i < ARRAYLEN ; i++) {

lstInt[i] = ((int) (Math.random() * 100));

}


inSort.printArray(lstInt);

inSort.insertSort(lstInt);



inSort.printArray(lstInt);


int x = 0;

int find = inSort.BinarySearchRecursive(lstInt, 0, ARRAYLEN - 1,

lstInt[x = (int) (Math.random() * ARRAYLEN )]);

if (find >= 0) {

System.out.println("Found Recursive " + lstInt[x]

+ " @ location : " + (find + 1));

}

x = 0;

find = inSort.BinarySearchIterative(lstInt, 0, ARRAYLEN - 1,

lstInt[x = (int) (Math.random() * ARRAYLEN )]);

if (find >= 0) {

System.out.println("Found Iterative " + lstInt[x]+ " @ location : " + (find + 1));

}

System.out.println();

}

public void unnamedSort(Integer[] lst) {

int temp = 0;







Sum of X Numbers in an Array21 April 2011

Problem : Find if in a sorted array the sum of any 2 (or 3) of the elements equals a given sum.

Source Code:

import java.util.Arrays;

public class SumOfNosInArray {

/**

* @param args

*/


public static int low = 0; public static int high = 0;

public static int start = 0;



SumOfNosInArray sna = new SumOfNosInArray();

int[] arr = new int[ARRAYLEN ];


arr[i] = ((int) (Math.random() * 10)); // Range : 0 - 99

}

System.out.println("Initial :");

sna.printArrayInt(arr);Arrays.sort(arr);

System.out.println("Sorted :");

sna.printArrayInt(arr);

System.out.println("Sum of Two numbers Sequence...");

int sum = (int) (Math.random() * 19);

low = 0;

high = arr.length - 1;

if (sna.SumOfTwoNos(arr, sum)) {

System.out.println("Sum of " + arr[low ] + " and " +

arr[high]

+ " is " + sum);

} else {System.out.println("Sum " + sum + " not found");

}

System.out.println("Sum of Three numbers Sequence...");

sum = (int) (Math.random() * 28);

low = 0;


if (sna.SumOfThreeNos(arr, sum)) {



System.out.println("Sum of " + arr[start] + " and " +

arr[low ]

+ " and " + arr[high] + " is " + sum);

} else {

System.out.println("Sum " + sum + " not found");

}

}

public boolean SumOfTwoNos(int[] arr, int sum) {

int temp = 0;

while (low < high) {

System.out.println("Comparing " + arr[low ] + " and " +

arr[high]

+ " low = " + low + " high = " + high);

temp = arr[low ] + arr[high];

if (temp == sum) {

return true;

} else if (temp < sum) {

low ++;

} else {

high--;}

}

return false;

}

public boolean SumOfThreeNos(int[] arr, int sum) {

int temp = 0;

while (start < arr.length) {

System.out.println("For start = " + start + "...");

low = start + 1;


temp = sum - arr[start];

if (SumOfTwoNos(arr, temp)) {

return true;

}

start++;

}

return false;

}

public void printArrayInt(int[] arr) {

for (int i = 0; i < arr.length; i++) {

System.out.print(arr[i] + " ");

}


}

}



Sample Output:

Initial :

9 3 9 6 7 1 6 5 7 8

Sorted :

1 3 5 6 6 7 7 8 9 9

Sum of Two numbers Sequence...Comparing 1 and 9 low = 0 high = 9

Comparing 1 and 9 low = 0 high = 8








Sum 2 not found

Sum of Three numbers Sequence...

For start = 0...

Comparing 3 and 9 low = 1 high = 9Comparing 5 and 9 low = 2 high = 9



Sum of 1 and 5 and 8 is 14



Bubble Sort22 April 2011

Source Code:

/**

* @author rparumal

*

*/

public class BubbleSort {



BubbleSort bSort = new BubbleSort();

// Creation and population of the Input array

Integer[] lstInt = new Integer[ARRAYLEN ];

// Code for generating random input

/* * for (int i = 0; i < ARRAYLEN; i++) { lstInt[i] = ((int)

* (Math.random() * 100)); // Range : 0 - 99 }

*/

lstInt = new Integer[] { 10, 2, 3, 4, 5, 6, 7, 8, 9, 1 };


bSort.printArray(lstInt);


bSort.bubbleSortFunction(lstInt);



bSort.printArray(lstInt);

}

// Bubble Sort function

public void bubbleSortFunction(Integer[] arr) {

boolean swap = true;

int i = 0, j = 0, temp;

while (swap) {

swap = false;

j++;

for (i = 0; i < ARRAYLEN - j; i++) {

if (arr[i] > arr[i + 1]) {

temp = arr[i];

arr[i] = arr[i + 1];

arr[i + 1] = temp;

swap = true;}

}

System.out.print("Interation " + j + " : ");

this.printArray(arr);


}

return;

}



// Array printing function - Generic

public <T> void printArray(T[] a) {

for (T t : a) {

System.out.print(t + " ");

}

return;

}

}

Sample Output:

Before : 10 2 3 4 5 6 7 8 9 1

Interation 1 : 2 3 4 5 6 7 8 9 1 10

Interation 2 : 2 3 4 5 6 7 8 1 9 10

Interation 3 : 2 3 4 5 6 7 1 8 9 10

Interation 4 : 2 3 4 5 6 1 7 8 9 10Interation 5 : 2 3 4 5 1 6 7 8 9 10

Interation 6 : 2 3 4 1 5 6 7 8 9 10

Interation 7 : 2 3 1 4 5 6 7 8 9 10

Interation 8 : 2 1 3 4 5 6 7 8 9 10

Interation 9 : 1 2 3 4 5 6 7 8 9 10

Interation 10 : 1 2 3 4 5 6 7 8 9 10

After : 1 2 3 4 5 6 7 8 9 10



Lowest Index of Number23 April 2011

Problem:

Given a sorted array which contains repetitive elements, given a number return the lowest index of thenumber.

Source Code:import java.util.Arrays;

public class LowestIndexOfNumber {

/**

* Problem: Given a sorted array which contains repetitive elements,

given a

* number return the lowest index of the number.

*/




int[] arr = new int[ARRAYLEN ];

int search = 0;

System.out.print("Indices : 0 1 2 3 4 5 6 7 8 9");


System.out.print("Initial array : ");


arr[i] = (int) (Math.random() * 10);


}

search = (int) (Math.random() * 10);Arrays.sort(arr);


System.out.print("Sorted array : ");



}

int low = binSearch(arr, search, 0, ARRAYLEN - 1);

while (low > 0 && (arr[low - 1] == arr[low])) {

low--;

}


System.out.println("Lowest index of " + search + " = " + low);

}

public static int binSearch(int[] arr, int key, int left, int right) {

if (left <= right) {

int middle = (left + right) / 2;

if (arr[middle] == key) {

return middle;

} else if (arr[middle] < key) {

return binSearch(arr, key, middle + 1, right);

} else {



return binSearch(arr, key, left, middle - 1);

}

}

return -1;

}

}

Sample Output:

Indices : 0 1 2 3 4 5 6 7 8 9

Initial array : 3 5 4 9 1 6 5 2 3 3

Sorted array : 1 2 3 3 3 4 5 5 6 9

Lowest index of 3 = 2



Unique Chars in a String23 April 2011

Problem:

Implement an algorithm to determine if a string has all unique characters.What if you can not useadditional data structures?

Source Code: public class UnquieCharsInString {



if (isAllCharsUnique("zadhzk")) {

System.out.println("Some chars are NOT unique");

} else {

System.out.println("All chars are unique");}

}

public static boolean isAllCharsUnique(String str) {

int chk = 0, val;

for (int i = 0; i < str.length(); i++) {

val = str.charAt(i) - 'a';

System.out.println("CharAt[" + i + "] - a = " + val);

if ((chk & (1 << val)) > 0) {

System.out.println("Value = " + (chk & (1 << val)));

return true;

} else {

chk |= (1 << val);}

System.out.println("Chk = " + chk);

}

return false;

}

}

Sample Output:CharAt[0] - a = 25

Chk = 33554432

CharAt[1] - a = 0

Chk = 33554433CharAt[2] - a = 3

Chk = 33554441

CharAt[3] - a = 7

Chk = 33554569

CharAt[4] - a = 25

Value = 33554432

Some chars are NOT unique



Reverse C-Style String23 April 2011

Problem:

Write code to reverse a C-Style String. (C-String means that “abcd” is represented as five characters,including the null character.)

Source Code:

#include <stdio.h>

#include <conio.h>

void reverse(char *);

int main()

{

char str[20]; printf("Enter the string to be reversed : ");

gets(str);

reverse(str);

}

void reverse(char *str)

{

char *beg = str;

char *end = str;

char tmp;

if(str)

{

while(*end){

++end;

}

--end;

while(str<end)

{

tmp = *str;

*str++ = *end;

*end-- = tmp;

}

}

printf("Reversed string : %s", beg);

getch();

}

Sample Output:

Enter the string to be reversed : This Is A String

Reversed string : gnirtS A sI sihT



Stack Implementation (Array)25 April 2011

Implementation of a stack which takes Positive integer input using arrays.

Source Code:

public class StackImplementation {

static int STACKLEN = 10;

static int TOP = -1;

int[] stackArray;

final static private int PUSHCONST = 1;

final static private int POPCONST = 2;

final static private int PRINTCONST = 3;

final static private int EXITCONST = 4;


int c;

StackImplementation stack = new StackImplementation();

stack.stackArray = new int[STACKLEN ];

while (true) {

c = InputClass

.getInputIntScanner ("Enter the input choice\n(1

- Push 2 - Pop 3 - Print 4 - Exit) : ");

if (c <= 0) {

continue;

}

switch (c) {

case PUSHCONST :

c = InputClass.getInputIntScanner ("Enter the INT to

push : ");if (c <= 0) {

continue;

}

stack.push(c);

break;

case POPCONST :

System.out.println("Popped element = " +

stack.pop());

break;

case PRINTCONST :

stack.printStack();

break;

case EXITCONST :

System.out.println("Exiting Stack

Implementation...");

return;

}

}

}

public void push(int x) {

if (isStackFull()) {



System.out.println("The stack is Full");

return;

}

TOP ++;

stackArray[TOP ] = x;

}

public int pop() {

if (isStackEmpty()) {

System.out.println("The stack is Empty");

return -1;

}

return stackArray[TOP --];

}

public void printStack() {

if (isStackEmpty()) {

System.out.println("The stack is empty");

return;

}

System.out.print("Top ");for (int i = TOP ; i >= 0; i--) {

System.out.print(stackArray[i] + " ");

}


}

public boolean isStackEmpty() {

if (TOP < 0) {

return true;

} else {

return false;

}

}

public boolean isStackFull() {

if (TOP >= (STACKLEN - 1)) {

return true;

} else {

return false;

}

}

}

Sample Output:

Enter the input choice(1 - Push 2 - Pop 3 - Print 4 - Exit) :

1

Enter the INT to push :

34

Enter the input choice

(1 - Push 2 - Pop 3 - Print 4 - Exit) :

1


45





3

Top 45 34



1


89



1


56



3

Top 56 89 45 34



2 Popped element = 56



2

Popped element = 89



3

Top 45 34



4

Exiting Stack Implementation...



Queue Implementation (Array)25 April 2011

Implementation of a queue which takes Positive integer input using arrays.

Source Code:

public class QueueImplementation {

static int QUEUELEN = 10;

static int HEAD = 0;

static int TAIL = -1;

int[] queueArray;

final static private int ENQUEUECONST = 1;

final static private int DEQUEUECONST = 2;

final static private int PRINTCONST = 3;

final static private int EXITCONST = 4;


int c;

QueueImplementation queue = new QueueImplementation();

queue.queueArray = new int[QUEUELEN ];

while (true) {

c = InputClass

.getInputIntScanner ("Enter the input choice\n(1

- Enqueue 2 - Dequeue 3 - Print 4 - Exit) : ");

if (c <= 0) {

continue;

}

switch (c) {

case ENQUEUECONST :

c = InputClass.getInputIntScanner ("Enter the INT to

push : ");

if (c <= 0) {

continue;

}

queue.enqueue(c);

break;

case DEQUEUECONST :

System.out.println("Popped element = " +

queue.dequeue());

break;

case PRINTCONST :

queue.printQueue();

break;case EXITCONST :

System.out.println("Exiting Queue

Implementation...");

return;

}

}

}

public void enqueue(int x) {



if (isQueueFull()) {

System.out.println("The queue is full...");

return;

}

if (TAIL == (QUEUELEN - 1)) {

TAIL = 0;

} else {

TAIL++;

}

queueArray[TAIL] = x;

}

public int dequeue() {

if (isQueueEmpty()) {

System.out.println("The queue is empty...");

return -1;

}

int tmp = queueArray[HEAD ];

if (HEAD == (QUEUELEN - 1)) {

HEAD = 0;

} else {HEAD ++;

}

return tmp;

}

public void printQueue() {

int tmpTail;

if (isQueueEmpty()) {

System.out.println("The Queue is empty");

return;

}

if (TAIL < HEAD ) {

tmpTail = TAIL + QUEUELEN ;

} else {

tmpTail = TAIL;

}

System.out.print("HEAD : ");

for (int i = HEAD ; i <= tmpTail; i++) {

System.out.print(queueArray[i % QUEUELEN ] + " ");

}

System.out.print(" : TAIL ");


}

public boolean isQueueEmpty() {

if (TAIL == -1 || HEAD == -1) {return true;

} else if (HEAD == TAIL) {

return true;

} else {

return false;

}

}

public boolean isQueueFull() {



if (TAIL == -1 || HEAD == -1) {

return false;

} else if (TAIL == (QUEUELEN - 1) && HEAD == 0) {

return true;

} else if (HEAD == (TAIL + 1)) {

return true;

} else {

return false;

}

}

}

Sample Output:


(1 - Enqueue 2 - Dequeue 3 - Print 4 - Exit) :

3

The Queue is empty

Enter the input choice(1 - Enqueue 2 - Dequeue 3 - Print 4 - Exit) :

`

Input integers only...



1


12



1


3 Enter the input choice


1


4



1


5



1

Enter the INT to push :6



3

HEAD : 12 3 4 5 6 : TAIL



1






Popped element = 3



2

Popped element = 4



2

Popped element = 5



3

HEAD : 6 7 8 9 10 11 50 : TAIL



3

HEAD : 6 7 8 9 10 11 50 : TAIL



4

Exiting Stack Implementation...

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