Why I am getting all zeroes as answer

Question

Merge Sort
https://code.sololearn.com/cSYoGofqmp0q/?ref=app

Answer 1

WeRaj 👑
In your original code, you need first like assign values in part1, part2 as

for(int n1=0; n<part1.length; n++)
part1[n1] = input[l+n1];

for(int n2=0; n2<part2.length; n2++)
part2[n2] = input[m+1+n2];

Here m is mid index value, l is lower bound which you are missing to take into count.
Add this before whole loop...

There you need some more changes I think...
Hope this helps to correct remaining ...

Answer 2

You are creating these two arrays
int[] part1 = new int[mid];
int[] part2 = new int[input.length-mid];

Which are initialized to 0s initially, and you are assigning these array values into input[] array..

All you need is like :

part1[k] = input[j]; instead of input[k] = part1[j];.

You are doing reverse assigning..
also first assign then apply sort.
Hope it helps....

Answer 3

Jayakrishna🇮🇳 sorry I forgot 😅🥲

Answer 4

Jayakrishna🇮🇳 it's not working bro
after doing suggested changes i am getting same array

Answer 5

Can you save the changes that Jayakrishna🇮🇳 suggested into the code here? At the moment it's still showing the same.
I did all 4 changes and the code ran with no problems.

Answer 6

Ausgrindtube Jayakrishna🇮🇳 see it's not working
array is not sorted

Answer 7

The code hasn't been updated. This is what you have.

if(part1[i]<part2[j])
{
input[k]=part1[i];
k++;
i++;
}
else {
input[k]=part2[j];
k++;
j++;
}
}
while(i<part1.length)
{
input[k]=part1[i];
k++;
i++;
}
while(j<part2.length){
input[k]=part2[j];
k++;
j++;
}
}

This is what Jayakrishna🇮🇳 said to do.
if(part1[i]<part2[j])
{
part1[i]= input[k];
k++;
i++;
}
else {
part2[j]= input[k];
k++;
j++;
}
}
while(i<part1.length)
{
part1[i]= input[k];
k++;
i++;
}
while(j<part2.length){
part2[j]= input[k];
k++;

Answer 8

WeRaj 👑 actually you have incorrect implementation of Mergesort algorithm. In algorithm, you need to split into parts of single valued and then merge those into a sorted order compare to original.. but you are dividing into 2 parts..
Creating array in merger function will create a new empty array each time.. You are dealing with empty array then.
My suggestion just give you assign correct way but that does not involving in sorting array...
Once read again algorithm then give another try...
Hope it helps...

Answer 9

Ausgrindtube just try to run the code after making changes still it doesn't give required output