IBM PLACEMENTS PAPERS LATEST 2007

1)Place a red ball in a urn and all the further balls in the other urn.The probability for picking out the red ball is now greater than 0.5.
2)If v<=2V then the position is (v*L)/(2*V) from the starting point else it is 2*L -(v*L)/(2*V) from the starting point.
4)If we know the process then we can kill it by killall -9 "process name" else we can kill it using its process id obtained by the command ps -x by kill -9 "processid" .
5)Top command displays all the Linux tasks running at that particular time.It provides their running time and the resources used.
6)The number appearing 2 times is (sum of all the numbers in the array) - (sum of the numbers from 1 to n).
For floating numbers multiply it with 100 and proceed.

• C program to create mirror copy of a tree
  

  Posted: Thu, 29 Nov 2007 23:10:59 -0600
  

  Question:Write a C program to create a mirror copy of a tree left nodes become right and right nodes become left)
  Solution:
  

  #include<stdio.h>
  struct binarysearchtree{
  int data;
  struct binarysearchtree* left;
  struct binarysearchtree* right;
  };
  typedef struct binarysearchtree* tree;
  
  tree mirror_copy(tree T)
  {
  if(T==NULL)
  return T;
  else
  {
  tree temp1=mirror_copy(T->left);
  tree temp2=mirror_copy(T->right);
  T->left=temp2;
  T->right=temp1;
  return T;
  }
  }
  

• Solutions to Questions on recursion
  

  Posted: Tue, 04 Dec 2007 04:28:58 -0600
  

  1)
  int Fibinocci(int n)
  {
  if(n==1)
  return 1;
  else
  n+Fibinocci(n-1);
  }
  
  2)
  void reverse(char*str)
  {
  if(*str != '\0')
  reverse(str+1);
  }
  
  3)
  int Factorial(int n)
  {
  if(n==1)
  return 1;
  else
  return(n*Factorial(n-1);
  }
  
  4)
  void MoveTower(int disk, int source, int dest, int spare):
  {
  if(disk == 1)
  printf("Move top disc from %d to %d\n",source,desc);
  else
  {
  MoveTower(disk - 1, source, spare, dest);
  printf("Move top disc from %d to %d\n",source,desc);
  // Step 2
  MoveTower(disk - 1, spare, dest, source);
  }
  }
  
  5)
  int gcd(int a,int b)
  {
  if(b==0)
  return(a);
  else
  return(gcd(b,a(mod)b);
  }
  

  
  6)
  arr is an array containing N integers.You can also change the program by keeping characters.k is initially 0.
  

  
  void permutation(int *arr, int N, int k)
  {
  static level = -1;
  level = level+1;
  arr[k] = level;
  
  if (level == N)
  {
  if(arr!=0)
  for(int i=0; i < N;i++)
  printf("%d",arr[i]);
  }
  else
  for (int i = 0; i < N; i++)
  if (arr[i] == 0)
  permutation(arr, N, i);
  level = level-1;
  arr[k] = 0;
  }
  
  7)void combinations(char*str,int no)
  {
  int temp1=0;
  int i,count,n=1,num,len;
  
  
  for(i=0;*(str+i)!='\0';i++);
  len=i;
  
  
  for(i=0;i < len;i++)
  n=2*n;
  temp=(int*)malloc(len*sizeof(int));
  for(i=0;i < len;i++)
  *(temp+i)=0;
  for(num=0;num <= n;num=num+1)
  {
  temp1=num;
  for(i=0;i < len;i++)
  {
  *(temp+i) = temp1%2;
  temp1=temp1/2;
  }
  count=0;
  for(i=0;i < len;i++)
  {
  if(*(temp+i)==1)
  count++;
  }
  if(count==no)
  {
  for(i=0;i < len;i++)
  {
  if(*(temp+i)==1)
  printf("%c",*(str+i));
  }
  printf("\n");
  
  
  
  
  }
  }
  

  
  8)
  Mergesort:a is an array of n intergers,temp is just a temporary array.low is initially 0 and high is n-1.
  

  
  void mergesort(int *a,int *temp,int low,int hi)
  {
  int mid;
  if(hi==low)
  {
  return;
  }
  else
  {
  mid=(low+hi)/2;
  mergesort(a,temp,low,mid);
  printf("1\n");
  mergesort(a,temp,mid+1,hi);
  printf("2\n");
  merge(a,temp,low,mid+1,hi);
  }
  }
  
  void merge(int a[],int temp[],int left,int rig,int r)
  {
  printf("%d %d %d\n",left,rig,r);
  int i,l,n,k;
  l=rig-1;
  k=left;
  n=r-left+1;
  while(left<=l&&rig<=r)
  {
  if(a[left]<=a[rig])
  temp[k++]=a[left++];
  else
  temp[k++]=a[rig++];
  }
  while(left<=l)
  temp[k++]=a[left++];
  while(rig<=r)
  temp[k++]=a[rig++];
  for(i=0;i < n;i++,r--)
  a[r]=temp[r];
  }
  

  
  Quicksort:a is an array of n integers.left is initially 0 and right is n-1.
  

  
  void quick(int *a, int left, int right)
  {
  int temp,i,k;
  temp=left;
  if (left>=right)
  {
  return;
  }
  
  
  k=(left+right)/2;
  swap(a,left,k);
  for (i=left+1;i<=right;i++)
  {
  if (a[i] < a[left])
  {
  swap(a,++temp,i);
  }
  }
  
  swap(a,left,temp); //swap a[left] and a[temp]
  quick(a,left,temp-1);
  quick(a,temp+1,right);
  }
  

• Minimum Value of a Binary Search Tree
  

  Posted: Thu, 29 Nov 2007 10:10:14 -0600
  

  Question:Write a C program to find the minimum value in a binary search tree.
  
  Solution:
  

  #include<stdio.h>
  struct binarysearchtree
  {
  int data;
  struct binarysearchtree* left;
  struct binarysearchtree* right;
  };
  typedef struct binarysearchtree* tree;
  
  tree min(tree T)
  {
  if (T==NULL)
  return NULL;
  else
  {
  if(T->left==NULL)
  return T;
  else
  return min(T->left);
  }
  }