VMWare Inc Interview Question SDETs
Country: India
There is O(n) solution for it. take two pointers for odd and even index, keep moving both pointers by 2 and stop when it violates the rule. Swap both odd and even index till indexes reach the end
Here is a C++ working code for it
#include "stdafx.h"
#include <iostream>
bool ArrangeEvenOddIndex(int evenOddArray[], int length)
{
if (length % 2 != 0)
{
return false;
}
if (evenOddArray == NULL || length < 2)
{
return true;
}
int oddIndex = 1;
int evenIndex = 0;
while (oddIndex < length && evenIndex < length)
{
while (evenIndex < length && evenOddArray[evenIndex] % 2 == 0)
{
evenIndex += 2;
}
while (oddIndex < length && evenOddArray[oddIndex] % 2 == 1)
{
oddIndex += 2;
}
// Swap Even and Odd
if (evenIndex < length && oddIndex < length)
{
int temp = evenOddArray[evenIndex];
evenOddArray[evenIndex] = evenOddArray[oddIndex];
evenOddArray[oddIndex] = temp;
}
}
return true;
}
void PrintArray(int arr[], int length)
{
for (int index = 0; index < length; index++)
{
std::cout << arr[index] << " ";
}
std::cout << std::endl;
}
int _tmain(int argc, _TCHAR* argv[])
{
int oddVernArray[] = {2, 5, 8, 6, 11, 23, 18, 1, 9, 10};
std::cout << "Before Arranging even and Odd" << std::endl;
PrintArray(oddVernArray, 10);
ArrangeEvenOddIndex(oddVernArray, 10);
std::cout << "After Arranging even and Odd" << std::endl;
PrintArray(oddVernArray, 10);
return 0;
}
public class ArrayEvenOdd {
private static int[] array = {2,4,3,45,21,6,22,5,9,111};
public static void main(String[] s)
{
int[] tempArray = new int[array.length];
int oddCounter = 0;
int evenCounter = 1;
for(int i=0;i<array.length;i++)
{
boolean isOdd = false;
if(i==array.length-1)
{
tempArray[i] = array[i];
}
else if(array[i]%2 != 0)
{
isOdd = true;
tempArray[oddCounter] = array[i];
}
else if(array[i]%2 == 0)
{
tempArray[evenCounter] = array[i];
}
if(isOdd)
oddCounter+=2;
else
evenCounter+=2;
}
for(int i=0;i<array.length;i++)
{
System.out.print(tempArray[i] + ",");
}
}
}
public class ArrayEvenOdd {
private static int[] array = {2,4,3,45,21,6,22,5,9,111};
public static void main(String[] s)
{
int[] tempArray = new int[array.length];
int oddCounter = 0;
int evenCounter = 1;
for(int i=0;i<array.length;i++)
{
boolean isOdd = false;
if(i==array.length-1)
{
tempArray[i] = array[i];
}
else if(array[i]%2 != 0)
{
isOdd = true;
tempArray[oddCounter] = array[i];
}
else if(array[i]%2 == 0)
{
tempArray[evenCounter] = array[i];
}
if(isOdd)
oddCounter+=2;
else
evenCounter+=2;
}
for(int i=0;i<array.length;i++)
{
System.out.print(tempArray[i] + ",");
}
}
}
public class ArrayEvenOdd {
private static int[] array = {2,4,3,45,21,6,22,5,9,111};
public static void main(String[] s)
{
int[] tempArray = new int[array.length];
int oddCounter = 0;
int evenCounter = 1;
for(int i=0;i<array.length;i++)
{
boolean isOdd = false;
if(i==array.length-1)
{
tempArray[i] = array[i];
}
else if(array[i]%2 != 0)
{
isOdd = true;
tempArray[oddCounter] = array[i];
}
else if(array[i]%2 == 0)
{
tempArray[evenCounter] = array[i];
}
if(isOdd)
oddCounter+=2;
else
evenCounter+=2;
}
for(int i=0;i<array.length;i++)
{
System.out.print(tempArray[i] + ",");
}
}
}
public class ArrayEvenOdd {
private static int[] array = {2,4,3,45,21,6,22,5,9,111};
public static void main(String[] s)
{
int[] tempArray = new int[array.length];
int oddCounter = 0;
int evenCounter = 1;
for(int i=0;i<array.length;i++)
{
boolean isOdd = false;
if(i==array.length-1)
{
tempArray[i] = array[i];
}
else if(array[i]%2 != 0)
{
isOdd = true;
tempArray[oddCounter] = array[i];
}
else if(array[i]%2 == 0)
{
tempArray[evenCounter] = array[i];
}
if(isOdd)
oddCounter+=2;
else
evenCounter+=2;
}
for(int i=0;i<array.length;i++)
{
System.out.print(tempArray[i] + ",");
}
}
}}
public class ArrayEvenOdd {
private static int[] array = {2,4,3,45,21,6,22,5,9,111};
public static void main(String[] s)
{
int[] tempArray = new int[array.length];
int oddCounter = 0;
int evenCounter = 1;
for(int i=0;i<array.length;i++)
{
boolean isOdd = false;
if(i==array.length-1)
{
tempArray[i] = array[i];
}
else if(array[i]%2 != 0)
{
isOdd = true;
tempArray[oddCounter] = array[i];
}
else if(array[i]%2 == 0)
{
tempArray[evenCounter] = array[i];
}
if(isOdd)
oddCounter+=2;
else
evenCounter+=2;
}
for(int i=0;i<array.length;i++)
{
System.out.print(tempArray[i] + ",");
}
}
}
public class ArrayEvenOdd {
private static int[] array = {2,24,98, 1,3,4,7,9};
public static void main(String[] s)
{
int evenArray[] = new int[array.length/2];
int oddArray[] = new int[array.length/2];
int evenIdx=0;
int oddIdx=0;
for(int i=0; i<array.length; i++){
if(array[i]%2==0)
evenArray[evenIdx++] = array[i];
else
oddArray[oddIdx++] = array[i];
}
for(int i=0; i<array.length; i++){
if(i%2==0)
array[i]= oddArray[i/2];
else
array[i] = evenArray[i/2];
}
for(int i=0;i<array.length;i++)
{
System.out.print(array[i] + ",");
}
}
}
A python script with the same logic as applied in rest of the answers
l = [2, 5, 8, 6, 11, 23, 18, 1, 9, 10]
even_ptr = 0
odd_ptr = 1
l_len = len(l)
while even_ptr < l_len and odd_ptr < l_len:
if l[even_ptr]%2 == 0:
even_ptr += 2
continue
if l[odd_ptr]%2 == 1:
odd_ptr += 2
continue
l[even_ptr], l[odd_ptr] = l[odd_ptr], l[even_ptr]
even_ptr += 2
odd_ptr += 2
print l
Python script with the same principal as applied in rest of the answers:-
l = [2, 5, 8, 6, 11, 23, 18, 1, 9, 10]
even_ptr = 0
odd_ptr = 1
l_len = len(l)
while even_ptr < l_len and odd_ptr < l_len:
if l[even_ptr]%2 == 0:
even_ptr += 2
continue
if l[odd_ptr]%2 == 1:
odd_ptr += 2
continue
l[even_ptr], l[odd_ptr] = l[odd_ptr], l[even_ptr]
even_ptr += 2
odd_ptr += 2
print l
public static void rearrange(int[] arr){
if(arr == null){
throw new NullPointerException();
}
int oddIndex = 0;
int evenIndex = 1;
while(evenIndex < arr.length && oddIndex < arr.length){
//find the next odd value to move
while(arr[evenIndex] % 2 == 0 && evenIndex< arr.length){
evenIndex+=2;
}
//find the next even value to move
while(arr[oddIndex] % 2 == 1 && oddIndex < arr.length){
oddIndex += 2;
}
//swap positions
if(oddIndex < arr.length && evenIndex < arr.length){
int temp = arr[evenIndex];
arr[evenIndex] = arr[oddIndex];
arr[oddIndex] = arr[evenIndex];
}
}
}
public void rearrange (int [] num) {
int odd = 0 , even = 1 ;
for (int i = 0 ; i < num.length ; ++i) {
while (odd < num.length && (num[odd] % 2) != 0) {
odd +=2 ;
}
while (even < num.length && (num[even] % 2) == 0 ) {
even +=2 ;
}
if (odd < num.length && (i % 2 != 0 && num[i] % 2 != 0)) {
swap (num,odd, i) ;
}
if (even < num.length && (i % 2 == 0 && num[i] % 2 == 0)) {
swap (num,even, i) ;
}
}
}
private void swap (int [] data , int i , int j){
int tmp = data [i] ;
data[i] = data[j] ;
data[j] = tmp ;
}
void fun(int *a,int n)
{
int c1,c2,temp,temp1,index,index1,j,i;
c1=0;
c2=0;
for(j=0;j<n;j++)
{
if(a[j]%2==0 && (j+1)%2==0)
continue;
else
{
if(a[j]%2>0 && (j+1)%2>0)
continue;
else
{
if(a[j]%2==0)
{
c1++;
temp=a[j];
index=j;
if(c2>0)
{
a[index1]=a[j];
a[j]=temp1;
c2=0;
}
}
else
{
c2++;
temp1=a[j];
index1=j;
if(c1>0)
{
a[index]=a[j];
a[j]=temp;
c1=0;
}
}
}
}
}
printf(" now required array:=>");
for(i=0;i<n;i++)
printf("%d ",a[i]);
}
void arrange_even_and_odd_numbers(vector<int>& arr)
{
int odd = 0;
int even = 1;
while (odd < arr.size() && even < arr.size())
{
if (arr[odd] & 1)
odd += 2;
else if (!(arr[even] & 1))
even += 2;
else
swap(arr[even], arr[odd]);
}
}
package algorithm;
public class question1 {
public void reArrangeArray(int[] data) {
boolean iFlip = false;
boolean jFlip = false;
for(int i = 0, j =1; (j < data.length && i < data.length); ) {
if(data[i]%2 == 0) {
i += 2;
} else {
iFlip = true;
}
if(data[j]%2 == 1) {
j += 2;
} else {
jFlip = true;
}
if(iFlip && jFlip) {
int tmp = data[i];
data[i] = data[j];
data[j] = tmp;
jFlip = false;
iFlip = false;
i += 2;
j += 2;
}
}
for(int i : data) {
System.out.println("data: " + i);
}
}
public static void main(String[] args) {
question1 q1 = new question1();
int[] data = {2,1,33,4,2,4,6,8,1,3,5,7,12,23,23,44};
q1.reArrangeArray(data);
}
}
package algorithm;
public class question1 {
public void reArrangeArray(int[] data) {
boolean iFlip = false;
boolean jFlip = false;
for(int i = 0, j =1; (j < data.length && i < data.length); ) {
if(data[i]%2 == 0) {
i += 2;
} else {
iFlip = true;
}
if(data[j]%2 == 1) {
j += 2;
} else {
jFlip = true;
}
if(iFlip && jFlip) {
int tmp = data[i];
data[i] = data[j];
data[j] = tmp;
jFlip = false;
iFlip = false;
i += 2;
j += 2;
}
}
for(int i : data) {
System.out.println("data: " + i);
}
}
public static void main(String[] args) {
question1 q1 = new question1();
int[] data = {2,1,33,4,2,4,6,8,1,3,5,7,12,23,23,44};
q1.reArrangeArray(data);
}
}
package algorithm;
public class question1 {
public void reArrangeArray(int[] data) {
boolean iFlip = false;
boolean jFlip = false;
for(int i = 0, j =1; (j < data.length && i < data.length); ) {
if(data[i]%2 == 0) {
i += 2;
} else {
iFlip = true;
}
if(data[j]%2 == 1) {
j += 2;
} else {
jFlip = true;
}
if(iFlip && jFlip) {
int tmp = data[i];
data[i] = data[j];
data[j] = tmp;
jFlip = false;
iFlip = false;
i += 2;
j += 2;
}
}
for(int i : data) {
System.out.println("data: " + i);
}
}
public static void main(String[] args) {
question1 q1 = new question1();
int[] data = {2,1,33,4,2,4,6,8,1,3,5,7,12,23,23,44};
q1.reArrangeArray(data);
}
}
package algorithm;
public class question1 {
public void reArrangeArray(int[] data) {
boolean iFlip = false;
boolean jFlip = false;
for(int i = 0, j =1; (j < data.length && i < data.length); ) {
if(data[i]%2 == 0) {
i += 2;
} else {
iFlip = true;
}
if(data[j]%2 == 1) {
j += 2;
} else {
jFlip = true;
}
if(iFlip && jFlip) {
int tmp = data[i];
data[i] = data[j];
data[j] = tmp;
jFlip = false;
iFlip = false;
i += 2;
j += 2;
}
}
for(int i : data) {
System.out.println("data: " + i);
}
}
public static void main(String[] args) {
question1 q1 = new question1();
int[] data = {2,1,33,4,2,4,6,8,1,3,5,7,12,23,23,44};
q1.reArrangeArray(data);
}
}
def arrangeOddEven(list):
rList = [0 for x in range(len(list))]
(oddIndex,evenIndex) = (0,1)
if (len(list) <=1):
return(list)
for i in list:
if (i % 2 == 0):
rList[evenIndex] = i
evenIndex+=2
else:
rList[oddIndex] = i
oddIndex+=2
return(rList)
list = [2,1,3,4,7,9,24,98]
print arrangeOddEven(list)
{def arrangeOddEven(list):
rList = [0 for x in range(len(list))]
(oddIndex,evenIndex) = (0,1)
if (len(list) <=1):
return(list)
for i in list:
if (i % 2 == 0):
rList[evenIndex] = i
evenIndex+=2
else:
rList[oddIndex] = i
oddIndex+=2
return(rList)
list = [2,1,3,4,7,9,24,98]
print arrangeOddEven(list)
}
The simplest O(N) solution would be :
public static void main(String[] args) {
int[] a = new int[] { 2, 1, 3, 4, 7, 9, 24, 98 };
evenoddNumbers(a);
for (int i = 0; i < a.length; i++) {
System.out.print(a[i] + " ");
}
}
public static boolean evenoddNumbers(int[] a) {
int odd = 0;
int even = 1;
int flag = 0;
for (int i = 0; i < a.length; i++) {
while (odd < a.length && even < a.length) {
if (a[odd] % 2 != 0 && a[even] % 2 == 0) {
odd = odd + 2;
even = even + 2;
} else if (a[odd] % 2 != 0) {
odd = odd + 2;
} else if (a[even] % 2 == 0) {
even = even + 2;
} else {
int temp = a[odd];
a[odd] = a[even];
a[even] = temp;
odd = odd + 2;
even = even + 2;
}
}
}
return true;
}
def placeEvenOdd(list1):
for i in xrange(len(list1)-1):
rem = 0
if (list1[i]%2)==((i+1)%2):
continue
else:
if list1[i] % 2 == 0:
rem = 1
for j in xrange(i+1, len(list1)):
if list1[j]%2 == rem:
list1[i], list1[j] = list1[j], list1[i]
break
print list1
if __name__ == "__main__":
placeEvenOdd([2,1,3,4,7,9,24,98])
Working code in C++
#include <iostream>
using namespace std;
void RearrangeArray(int iArr[], int iNum)
{
int iEvenIndex, iOddIndex, iEvenIndexFlag, iOddIndexFlag, iTempNum;
iEvenIndex = 1;
iOddIndex = 0;
iEvenIndexFlag = 0;
iOddIndexFlag = 0;
while(iEvenIndex < iNum && iOddIndex < iNum)
{
if(iArr[iEvenIndex]%2 == 0)
{
//Number is even
iEvenIndex += 2;
iEvenIndexFlag = 0;
}
else
{
iEvenIndexFlag = 1;
}
if(iArr[iOddIndex]%2 == 1)
{
//Number is odd
iOddIndex += 2;
iOddIndexFlag = 0;
}
else
{
iOddIndexFlag = 1;
}
if(iEvenIndexFlag == 1 && iOddIndexFlag == 1)
{
iTempNum = iArr[iEvenIndex];
iArr[iEvenIndex] = iArr[iOddIndex];
iArr[iOddIndex] = iTempNum;
iEvenIndex += 2;
iOddIndex += 2;
}
}
}
void PrintArray(int iArr[], int iNum)
{
for(int i=0; i<iNum; i++)
{
cout<<iArr[i]<<" ";
}
cout<<"\n";
}
int main()
{
int iArr[] = {2, 1, 3, 4, 7, 9, 24, 98};
int iNumOfElements;
iNumOfElements= sizeof(iArr)/sizeof(int);
//Print original array
cout<<"\nOriginal array: ";
PrintArray(iArr, iNumOfElements);
//Rearrange arary with even and odd numbers at respective places
RearrangeArray(iArr, iNumOfElements);
//Print rearranged array
cout<<"\nRearranged array: ";
PrintArray(iArr, iNumOfElements);
return 0;
}
class RearrangeOddEven
{
public static void main (String[] args) throws java.lang.Exception
{
int[] a = {2, 1, 3, 4, 7, 9, 24, 98};
rearrange(a);
System.out.println(Arrays.toString(a));
}
private static void swap(int i, int j, int[] a) {
int temp = a[i];
a[i] = a[j];
a[j] = temp;
}
public static void rearrange(int[] a) {
for (int i=0; i<a.length-1; i++) {
if (a[i] % 2 == 0 && (i + 1 ) % 2 != 0) {
int oddIndex = getFirstOddIndex(a, i+1);
if (oddIndex != -1) {
swap(oddIndex, i, a);
}
} else if (a[i] % 2 != 0 && (i + 1 ) % 2 == 0) {
int evenIndex = getFirstEvenIndex(a, i+1);
if (evenIndex != -1) {
swap(evenIndex, i, a);
}
}
}
}
private static int getFirstOddIndex(int[] a, int startIndex) {
for (int i=startIndex; i<a.length; i++) {
if (a[i] % 2 != 0 && (i + 1) % 2 == 0) {
return i;
}
}
return -1;
}
private static int getFirstEvenIndex(int[] a, int startIndex) {
for (int i=startIndex; i<a.length; i++) {
if (a[i] % 2 == 0 && (i + 1) % 2 != 0) {
return i;
}
}
return -1;
}
}
class Ideone
{
public static void main (String[] args) throws java.lang.Exception
{
int[] a = {2, 1, 3, 4, 7, 9, 24, 98};
rearrange(a);
System.out.println(Arrays.toString(a));
}
private static void swap(int i, int j, int[] a) {
int temp = a[i];
a[i] = a[j];
a[j] = temp;
}
public static void rearrange(int[] a) {
for (int i=0; i<a.length-1; i++) {
if (a[i] % 2 == 0 && (i + 1 ) % 2 != 0) {
int oddIndex = getFirstOddIndex(a, i+1);
if (oddIndex != -1) {
swap(oddIndex, i, a);
}
} else if (a[i] % 2 != 0 && (i + 1 ) % 2 == 0) {
int evenIndex = getFirstEvenIndex(a, i+1);
if (evenIndex != -1) {
swap(evenIndex, i, a);
}
}
}
}
private static int getFirstOddIndex(int[] a, int startIndex) {
for (int i=startIndex; i<a.length; i++) {
if (a[i] % 2 != 0 && (i + 1) % 2 == 0) {
return i;
}
}
return -1;
}
private static int getFirstEvenIndex(int[] a, int startIndex) {
for (int i=startIndex; i<a.length; i++) {
if (a[i] % 2 == 0 && (i + 1) % 2 != 0) {
return i;
}
}
return -1;
}
}
class Ideone
{
public static void main (String[] args) throws java.lang.Exception
{
int[] a = {2, 1, 3, 4, 7, 9, 24, 98};
rearrange(a);
System.out.println(Arrays.toString(a));
}
private static void swap(int i, int j, int[] a) {
int temp = a[i];
a[i] = a[j];
a[j] = temp;
}
public static void rearrange(int[] a) {
for (int i=0; i<a.length-1; i++) {
if (a[i] % 2 == 0 && (i + 1 ) % 2 != 0) {
int oddIndex = getFirstOddIndex(a, i+1);
if (oddIndex != -1) {
swap(oddIndex, i, a);
}
} else if (a[i] % 2 != 0 && (i + 1 ) % 2 == 0) {
int evenIndex = getFirstEvenIndex(a, i+1);
if (evenIndex != -1) {
swap(evenIndex, i, a);
}
}
}
}
private static int getFirstOddIndex(int[] a, int startIndex) {
for (int i=startIndex; i<a.length; i++) {
if (a[i] % 2 != 0 && (i + 1) % 2 == 0) {
return i;
}
}
return -1;
}
private static int getFirstEvenIndex(int[] a, int startIndex) {
for (int i=startIndex; i<a.length; i++) {
if (a[i] % 2 == 0 && (i + 1) % 2 != 0) {
return i;
}
}
return -1;
}
}
public class ArrangArray {
public static void main(String[] args) {
int[] input = { 2, 1, 3, 4, 7, 9, 24, 98, 100 };
int[] temparray = new int[input.length];
int odd_index = 0, even_index = 1;
if (validateinputArray(input)) {
for (int i : input) {
if (i % 2 == 0) {
temparray[even_index] = i;
even_index += 2;
} else {
temparray[odd_index] = i;
odd_index += 2;
}
}
System.out.println("new array::" + Arrays.toString(temparray));
} else
System.out.println("invalid input::" + Arrays.toString(input));
}
public static boolean validateinputArray(int[] input) {
boolean rValue = false;
int evenNumbrs = 0;
int oddNumbers = 0;
for (int i : input) {
if (i % 2 == 0)
evenNumbrs++;
else
oddNumbers++;
}
if (input.length % 2 == 0) {
if (evenNumbrs == oddNumbers)
rValue = true;
} else if (oddNumbers == (evenNumbrs + 1))
rValue = true;
return rValue;
}
}
package com.my.practice;
public class ReArrangeNumbers {
public static void main(String[] args) {
int[] a = { 1, 3, 2, 5, 6, 8, 9 };
for(int each : a){
System.out.print( each + " ");
}
System.out.println();
System.out.println("---------After----------");
int totalOddArrayPositions = 0, totalOddNumbers = 0;
int totalEvenArrayPositions = 0, totalEvenNumbers = 0;
for (int i = 1; i < a.length + 1; i++) {
if (i % 2 == 0) {
totalEvenArrayPositions++;
} else {
totalOddArrayPositions++;
}
if (a[i - 1] % 2 == 0) {
totalEvenNumbers++;
} else {
totalOddNumbers++;
}
}
if ((totalEvenArrayPositions == totalEvenNumbers) && (totalOddArrayPositions == totalOddNumbers)) {
for (int i = 1; i < a.length + 1; i++) {
if ((i % 2 == 0) && (a[i - 1] % 2 == 0)) {
continue;
} else if ((i % 2 == 1) && (a[i - 1] % 2 == 1)) {
continue;
}
else {
int temp = a[i-1];
a[ i - 1] = a [i];
a[i] = temp;
}
}
} else {
System.out.println("Re-Arrangement is NOT Possible");
}
for(int each : a){
System.out.print( each + " ");
}
}
}
package com.my.practice;
public class ReArrangeNumbers {
public static void main(String[] args) {
int[] a = { 1, 3, 2, 5, 6, 8, 9 };
for(int each : a){
System.out.print( each + " ");
}
System.out.println();
System.out.println("---------After----------");
int totalOddArrayPositions = 0, totalOddNumbers = 0;
int totalEvenArrayPositions = 0, totalEvenNumbers = 0;
for (int i = 1; i < a.length + 1; i++) {
if (i % 2 == 0) {
totalEvenArrayPositions++;
} else {
totalOddArrayPositions++;
}
if (a[i - 1] % 2 == 0) {
totalEvenNumbers++;
} else {
totalOddNumbers++;
}
}
if ((totalEvenArrayPositions == totalEvenNumbers) && (totalOddArrayPositions == totalOddNumbers)) {
for (int i = 1; i < a.length + 1; i++) {
if ((i % 2 == 0) && (a[i - 1] % 2 == 0)) {
continue;
} else if ((i % 2 == 1) && (a[i - 1] % 2 == 1)) {
continue;
}
else {
int temp = a[i-1];
a[ i - 1] = a [i];
a[i] = temp;
}
}
} else {
System.out.println("Re-Arrangement is NOT Possible");
}
for(int each : a){
System.out.print( each + " ");
}
}
}
{
package com.my.practice;
public class ReArrangeNumbers {
public static void main(String[] args) {
int[] a = { 1, 3, 2, 5, 6, 8, 9 };
for(int each : a){
System.out.print( each + " ");
}
System.out.println();
System.out.println("---------After----------");
int totalOddArrayPositions = 0, totalOddNumbers = 0;
int totalEvenArrayPositions = 0, totalEvenNumbers = 0;
for (int i = 1; i < a.length + 1; i++) {
if (i % 2 == 0) {
totalEvenArrayPositions++;
} else {
totalOddArrayPositions++;
}
if (a[i - 1] % 2 == 0) {
totalEvenNumbers++;
} else {
totalOddNumbers++;
}
}
if ((totalEvenArrayPositions == totalEvenNumbers) && (totalOddArrayPositions == totalOddNumbers)) {
for (int i = 1; i < a.length + 1; i++) {
if ((i % 2 == 0) && (a[i - 1] % 2 == 0)) {
continue;
} else if ((i % 2 == 1) && (a[i - 1] % 2 == 1)) {
continue;
}
else {
int temp = a[i-1];
a[ i - 1] = a [i];
a[i] = temp;
}
}
} else {
System.out.println("Re-Arrangement is NOT Possible");
}
for(int each : a){
System.out.print( each + " ");
}
}
}
}
package com.my.practice;
public class ReArrangeNumbers {
public static void main(String[] args) {
int[] a = { 1, 3, 2, 5, 6, 8, 9 };
for(int each : a){
System.out.print( each + " ");
}
System.out.println();
System.out.println("---------After----------");
int totalOddArrayPositions = 0, totalOddNumbers = 0;
int totalEvenArrayPositions = 0, totalEvenNumbers = 0;
for (int i = 1; i < a.length + 1; i++) {
if (i % 2 == 0) {
totalEvenArrayPositions++;
} else {
totalOddArrayPositions++;
}
if (a[i - 1] % 2 == 0) {
totalEvenNumbers++;
} else {
totalOddNumbers++;
}
}
if ((totalEvenArrayPositions == totalEvenNumbers) && (totalOddArrayPositions == totalOddNumbers)) {
for (int i = 1; i < a.length + 1; i++) {
if ((i % 2 == 0) && (a[i - 1] % 2 == 0)) {
continue;
} else if ((i % 2 == 1) && (a[i - 1] % 2 == 1)) {
continue;
}
else {
int temp = a[i-1];
a[ i - 1] = a [i];
a[i] = temp;
}
}
} else {
System.out.println("Re-Arrangement is NOT Possible");
}
for(int each : a){
System.out.print( each + " ");
}
}
}
static void swap(int[] a, int i, int j)
{
var temp = a[i];
a[i] = a[j];
a[j] = temp;
}
static void Main(string[] args)
{
int[] a = { 2, 1, 3, 4, 7, 9, 24, 28 };
int lastie = -1, lastio = -1, ie, io;
for (ie=0,io=1; ie < a.Length && io < a.Length; ie+=2, io += 2)
{
if (a[ie] % 2 != 0)
{
if (lastie >= 0)
{
swap(a, ie, lastie);
lastie = -1;
}
else lastio = ie;
}
if (a[io] % 2 == 0)
{
if (lastio >= 0)
{
swap(a, io, lastio);
lastio = -1;
}
else lastie = io;
}
}
}
#In python, I have written this code for this purpose -
# Idea is basically create a table of column index_type(even/odd), value_type and action
index_type value_type action
even even continue
odd odd continue
odd even seek for next even index, stop when first odd value is found
even odd seek for next odd index, stop when first even value is found
Implementation is below - (pre-condition can be added : len(all even) == len(all odd), i haven't added this for simplicity)
def even_at_even_odd_at_odd(a):
n = len(a)
for i in enumerate(a):
index = i[0]
item = i[1]
if (index+1)%2 == 0 and item%2 == 0:
continue
elif (index+1)%2 != 0 and item%2 != 0:
continue
elif (index+1)%2 == 0 and item%2 != 0:
next_odd=index+1
while next_odd<n-2 and a[next_odd]%2 != 0:
next_odd = next_odd +2
a[index], a[next_odd] = a[next_odd], a[index]
elif (index+1)%2 != 0 and item%2 == 0:
next_even=index+1
while next_even<n-2 and a[next_even]%2 == 0:
next_even = next_even +2
a[index], a[next_even] = a[next_even], a[index]
print a
if __name__ == "__main__"
a = [36, 2, 17, 19, 5, 4, 6, 8, 7, 9, 16, 18, 15, 13]
even_at_even_odd_at_odd(a)
public static void rearrange(int[] A){
List<Integer> l = new ArrayList<Integer>();
for(int n=A.length-1; n>=1; n--){
if(((n+1)%2 ==1 && A[n]%2==0) || ((n+1)%2 ==0 && A[n]%2==1))
l.add(n);
for(int j=0; j<A.length; j++)
{
if(l.contains(j) && n!=0 && A[(j-1)]%2 == 0)
{
int temp = A[j];
A[j] = A[j-1];
A[j-1] = temp;
}
}
}
}
public static void rearrange(int[] A){
List<Integer> l = new ArrayList<Integer>();
for(int n=A.length-1; n>=1; n--){
if(((n+1)%2 ==1 && A[n]%2==0) || ((n+1)%2 ==0 && A[n]%2==1))
l.add(n);
for(int j=0; j<A.length; j++)
{
if(l.contains(j) && n!=0 && A[(j-1)]%2 == 0)
{
int temp = A[j];
A[j] = A[j-1];
A[j-1] = temp;
}
}
}
}
Simple approach using O(n) algo.
Just need to keep two pointers for odd and even index and increase by 2 each, swap odd and even as required
- pc May 26, 2015#include "stdafx.h" #include <iostream> bool ArrangeEvenOddIndex(int evenOddArray[], int length) { if (length % 2 != 0) { return false; } if (evenOddArray == NULL || length < 2) { return true; } int oddIndex = 1; int evenIndex = 0; while (oddIndex < length && evenIndex < length) { while (evenIndex < length && evenOddArray[evenIndex] % 2 == 0) { evenIndex += 2; } while (oddIndex < length && evenOddArray[oddIndex] % 2 == 1) { oddIndex += 2; } // Swap Even and Odd if (evenIndex < length && oddIndex < length) { int temp = evenOddArray[evenIndex]; evenOddArray[evenIndex] = evenOddArray[oddIndex]; evenOddArray[oddIndex] = temp; } } return true; } void PrintArray(int arr[], int length) { for (int index = 0; index < length; index++) { std::cout << arr[index] << " "; } std::cout << std::endl; } int _tmain(int argc, _TCHAR* argv[]) { int oddVernArray[] = {2, 5, 8, 6, 11, 23, 18, 1, 9, 10}; std::cout << "Before Arranging even and Odd" << std::endl; PrintArray(oddVernArray, 10); ArrangeEvenOddIndex(oddVernArray, 10); std::cout << "After Arranging even and Odd" << std::endl; PrintArray(oddVernArray, 10); return 0; }