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Amazon Interview Question for Software Engineer/Developer (0 - 2 Years)

(7 posts)

1. 

   Brainless
   guest
   Posted 5 months ago #
   
   

   The next highest number in the given sequence
   ex: input:213476-->213467
   54321--> -1

2. 

   WgpShashank
   guest
   Posted 5 months ago #
   
   

   we have to generate the next higher permutation of given number isn't it ?

   1) From the end, keep decrementing till A[i] < A[i+1]..

   2) Now, find the closest element , greater than equal, to A[i] in

   A[i+1 ... n]. Say, the index of the found element is "j".

   3) Swap (A[i], A[j])

   4) Reverse array A[i+1 .. n]

   Example:

   Input 14532

   output 15234..

   1) 4 is the value where A[i] < A[i+1] when scanned from the end.

   2) The closest element grater than equal to 4 in the subarray 532 is

   5.

   3) Swap (4,5) : 14532 -> 15432

   4) Now, as we have identified in step 1 the index of i, we need to

   reverse the array from A[i+1, n] i.e. in 15(432) (432) needs to be

   reversed and hence we will get 15234...

   You Can find wiki permutation page for more detail :)

   let me know if any other method you are aware of ?

3. 

   Dedicated Programmer
   Member
   Posted 4 months ago #
   
   

   @WgpShashank ,
   can u explain me ur program for number: 15432
   I think here it gives wrong output.

4. 

   aks
   Member
   Posted 4 months ago #
   
   

   Add 9 repeatedly to the number until you arrive at a number which contains only the digits of original number. That will give you the expected number if there is one.

   To be optimized

   1. How long addition of 9 should repeat (Eg, for 12345, It is enough if we check till 54321)
   2. Method to check if it contains digits of Original number (Eg, 12354+9=12363. Compare(12354, 12363))

5. 

   sangeeta
   guest
   Posted 3 months ago #
   
   

   You can find solution here:
   http://www.ardendertat.com/2012/01/02/programming-interview-questions-24-find-next-higher-number-with-same-digits/

6. 

   PsychoCoder
   Member
   Posted 3 months ago #
   
   

   #include<stdio.h>
   #include<string.h>
   #include<stdlib.h>
   
   char* getNextHighest (char *str) {
     int len = strlen (str);
     int i = len-2, index, minIndex ;
     char ch, minHighest;
   
     // Searching where we find str[i]<str[i+1] (pivot index)
     while (i>=0) {
       if (str[i] < str[i+1])
         break ;
       i -- ;
     }
   
     // Numbers are in decreasing order
     if (i<0)
       return "-1" ;
   
     index = minIndex = i+1 ;
     minHighest = str[index];
   
     // Search for the number which is equal or just higher than pivot index element
     while (index<len) {
       if ( (str[i] < str[index]) && (str[minIndex] >= str[index]) ) {
         minIndex = index ;
       } else break ;
       index ++ ;
     }
     ch = str[minIndex] ;
     str[minIndex] = str[i] ;
     str[i]= ch ;
   
     index = i+1 ;
     i = len-1;
   
     // Reverse the all the elements in the right to the pivot element
     while (index<i) {
       ch = str[index] ;
       str[index] = str[i] ;
       str[i]= ch ;
       index ++ ;
       i--;
     }
   
     return str ;
   }
   
   int main() {
     char buf[20] ;
     int num ;
     printf ( "\nEnter the number :\t" ) ;
     scanf ( "%d", &num );
     sprintf (buf,"%d",num) ;
     printf ("\nNext highest number of %d is %s\n", num, getNextHighest(buf) );
     return 0;
   }

7. 

   Nages
   Member
   Posted 3 months ago #
   
   

   Input = 11532
   Expected output = 12135

   1) Find a number (say the index as x) from right to left, which is smaller than its right. ( if can not find, then return -1)
   1 (1) 5 3 2
   2) Find a number (say the index as y) which is the least max of value of xth index, from the x to end, swap x and y
   1 (1) [5 3 (2)] ==> 1 (2) [5 3 (1)]
   3) Sort from x+1th index till end
   1 (2) [ 1 3 5 ] == > 12135

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