Amazon Interview Question for SDE-2s


Team: Product Details Page
Country: India
Interview Type: In-Person




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0
of 2 vote

Can you give an example ???

- hnatsu March 04, 2016 | Flag Reply
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0
of 0 vote

What is meaning of non-increasing and non-decreasing sub-sequence?

- Ra's March 04, 2016 | Flag Reply
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0
of 0 vote

Can you please post your solution

- Harman March 06, 2016 | Flag Reply
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0
of 0 vote

Can you please post your solution

- Harmanbir.rai March 06, 2016 | Flag Reply
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0
of 0 vote

If you had already done this, then now do you u want some other solution ?

- ash.taunk3 March 06, 2016 | Flag Reply
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0
of 0 vote

A dynamic solution plus caching technique is implemented. In the best case it has O((n-m)^2) computation complexity. And it has O(n*m) space complexity. Details: cpluspluslearning-petert.blogspot.co.uk/2016/03/dynamic-programming-find-difference-of.html

Test

void TestFindDiffOfAscAndDescSeq()
{
    {
        bool exceptionCaught = false;
        try {
            const std::vector<int> input;
            GetDiffOfAscendingAndDescedningSequence(input, 2);
        }
        catch (const InvalidParamException &e) {
            exceptionCaught = true;
        }
        catch (...)
        {
        }
        assert(exceptionCaught == true);

        exceptionCaught = false;
        try {
            const std::vector<int> input = { 1, 2, 3 };
            GetDiffOfAscendingAndDescedningSequence(input, 1);
        }
        catch (const InvalidParamException &e) {
            exceptionCaught = true;
        }
        catch (...)
        {
        }
        assert(exceptionCaught == true);

        exceptionCaught = false;
        try {
            const std::vector<int> input = { 1, 2, 3 };
            GetDiffOfAscendingAndDescedningSequence(input, 4);
        }
        catch (const InvalidParamException &e) {
            exceptionCaught = true;
        }
        catch (...)
        {
        }
        assert(exceptionCaught == true);

        exceptionCaught = false;
        try {
            const std::vector<int> input = { 1, 2, 3 };
            GetDiffOfAscendingAndDescedningSequence(input, 1);
        }
        catch (const InvalidParamException &e) {
            exceptionCaught = true;
        }
        catch (...)
        {
        }
        assert(exceptionCaught == true);
    }
    {
        const std::vector<int> input = { 1, 2, 3, 4, 5, 6, 7, 8 };
        assert(GetDiffOfAscendingAndDescedningSequence(input, 2) == 28);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 3) == 56);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 4) == 70);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 5) == 56);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 6) == 28);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 7) == 8);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 8) == 1);
    }
    {
        const std::vector<int> input = { 8, 7, 6, 5, 4, 3, 2, 1 };
        assert(GetDiffOfAscendingAndDescedningSequence(input, 2) == -28);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 3) == -56);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 4) == -70);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 5) == -56);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 6) == -28);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 7) == -8);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 8) == -1);
    }
    {
        const std::vector<int> input = { 8, 7, 6, 5, 4, 3, 2, 1, 11, 12, 13, 14, 15, 16, 17, 18 };
        assert(GetDiffOfAscendingAndDescedningSequence(input, 2) == 8*8); 
        assert(GetDiffOfAscendingAndDescedningSequence(input, 3) == 8*28); 
        assert(GetDiffOfAscendingAndDescedningSequence(input, 4) == 8*56);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 5) == 8*70);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 6) == 8*56);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 7) == 8*28);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 8) == 8*8);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 9) == 8);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 10) == 0);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 11) == 0);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 12) == 0);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 13) == 0);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 14) == 0);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 15) == 0);
        assert(GetDiffOfAscendingAndDescedningSequence(input, 16) == 0);
    }

}

- peter tang March 26, 2016 | Flag Reply
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0
of 0 vote

i implemented with a bit of dp complexity would be n^2*m

class Q1 {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		
		int[] arr = {1,2,3,-1,9,8};
		int n =6;
		int m=3;
		if(m==1){
			System.out.println(0);
			return;
		}
		
	   
		int[] decP  = new int[n];
		int[] incP = new int[n];
		int[] dec = new int[n];
		int[] inc = new int[n];
		for(int i=0;i<n;i++){
			decP[i]= 1;
			incP[i]=1;
		}
		for(int l=2;l<=m;l++){
			for(int i=l-1;i<n;i++){
				dec[i] = 0;
				inc[i] = 0;
				for(int j=l-2;j<i;j++){
				if((arr[i]<=arr[j]))
					dec[i] = decP[j]+dec[i];
				
					if(arr[i]>=arr[j]){
					inc[i]  = incP[j]+inc[i];
					
					}
				}
			}
			decP = dec.clone();
			incP = inc.clone();
		}
		int diff=0;
		
		for(int i =(m-1);i<n;i++)
			diff =diff+inc[i]-dec[i];
		
		System.out.println(diff);
			

	}

}

- bhanu April 02, 2016 | Flag Reply
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0
of 0 vote

public static void main(String[] args) {
        /**
         * n = 11
         * arr = {1, 2, 3, 4, 1, 8, 9, 11, 2, 1, 0}
         * m = 3
         * increasing sequences of size 3 = [(1,2,3),(2,3,4),(1,8,9),(8,9,11)]
         * decreasing sequences of size 3 = [(11,2,1),(2,1,0)]
         * diff =
         */

        int sequence[] = {1, 2, 3, 4, 1, 8, 9, 11, 2, 1, 0};
        int incCount[] = new int[11];
        int decCount[] = new int[11];
        int diff = 0;

        incCount[0] = 1;
        decCount[0] = 1;
        for( int i = 1; i <= sequence.length - 1; i++ ){
            if( sequence[i] >= sequence[i-1] ) {
                incCount[i] = incCount[i-1] + 1;
                decCount[i] = 1;
            }else{
                incCount[i] = 1;
                decCount[i] = decCount[i-1] + 1;
            }
        }

        for( int i = 1; i <= sequence.length - 1; i++ ){
            if( incCount[i] >= 3) diff += 1;
            if( decCount[i] >= 3) diff -= 1;
        }

        System.out.println(Math.abs(diff));

    }

- tarun.gupta.pec April 07, 2016 | Flag Reply
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0
of 0 vote

clean code.

- ravinder April 11, 2016 | Flag Reply
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0
of 0 vote

package com.mayank.Amazon;

import com.sun.org.apache.xalan.internal.xsltc.compiler.sym;

public class SequenceTest {

public static void main(String[] args) {
/**
* n = 11
* arr = {1, 2, 3, 4, 1, 8, 9, 11, 2, 1, 0}
* m = 3
* increasing sequences of size 3 = [(1,2,3),(2,3,4),(1,8,9),(8,9,11)]
* decreasing sequences of size 3 = [(11,2,1),(2,1,0)]
* diff =
*/

int arr[]={1, 2, 3, 4, 1, 8, 9, 11, 2, 1, 0};
int n =11;
int m =3;
int incCount=0;
int decCount=0;
int i=0;

for(i=0; i<=n-m ;i++)
{

if(arr[i]<arr[i+1])
{
if(arr[i+1]<arr[i+2])
{
incCount=incCount+1;

}
}
else if(arr[i]>arr[i+1]){
if(arr[i+1]>arr[i+2])
{
decCount=decCount+1;
}
}
}
System.out.println(incCount);
System.out.println(decCount);
System.out.println("difference is -----"+(Math.abs(incCount)-Math.abs(decCount)));
}


}

- Mayank April 13, 2016 | Flag Reply
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0
of 0 vote

package com.mayank.Amazon;

import com.sun.org.apache.xalan.internal.xsltc.compiler.sym;

public class SequenceTest {
	
	public static void main(String[] args) {
        /**
         * n = 11
         * arr = {1, 2, 3, 4, 1, 8, 9, 11, 2, 1, 0}
         * m = 3
         * increasing sequences of size 3 = [(1,2,3),(2,3,4),(1,8,9),(8,9,11)]
         * decreasing sequences of size 3 = [(11,2,1),(2,1,0)]
         * diff =
         */
	
			int arr[]={1, 2, 3, 4, 1, 8, 9, 11, 2, 1, 0};
			int n =11;
			int m =3;
			int incCount=0;
			int decCount=0;
			int i=0;
			
			for(i=0; i<=n-m ;i++)
			{
				
				if(arr[i]<arr[i+1])
				{
					if(arr[i+1]<arr[i+2])
					{
						incCount=incCount+1;
						
					}
				}
				else if(arr[i]>arr[i+1]){
					if(arr[i+1]>arr[i+2])
					{
						decCount=decCount+1;
					}
				}
			}
			System.out.println(incCount);
			System.out.println(decCount);
			System.out.println("difference is -----"+(Math.abs(incCount)-Math.abs(decCount)));
	}

}

- Mayank April 13, 2016 | Flag Reply
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0
of 0 vote

Hey @mruday4friendz can you please be little bit helpful? What is xyz? What was your bug and Brute force method? Why u did not explained your approach clearly? Why this suspense? I guess you want people to solve it by themselves which is nice but as you can see we r stuck here as clearly answer is not known.
So I request you to please provide your detailed answer and give some explanations. Please provide some help here.

- Poon August 17, 2016 | Flag Reply


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