Subsetsumcpp dry run

#1

could you plz tell me how will these piece of code would dry run?

case 1:-
subsetsum(a,sum+a[i],i+1,n,count);
subsetsum(a,sum,i+1,n,count);

case 2:-
subsetsum(a,i+1,sum,count);
sum+=a[i];
subsetsum(a,i+1,sum,count);

#2

@Kush_1312,
What are you trying to do here in this code? Please tell the context so we can help you dry run it.

#3

Mike is a very passionate about sets. Lately, he is busy solving one of the problems on sets. He has to find whether if the sum of any of the non-empty subsets of the set A is zero.
The question is this.

i wanted to know how would these recursive call would execute?
in case 1 and case2.

#4


here is the codes

#5

@Kush_1312,
Please give a link to the problem as well.

#6

@Kush_1312,
The recursion is pretty straight forward,

  • Standing on a element you have two choices, either to or not to include it in the subset,

Case 1: Include the current element:

This would lead to addition of current element to the subset sum, thus subsetsum(a,sum+a[i],i+1,n,count);

Case 2: Do not include the current element:

This would not affect the subset sum, thus subsetsum(a,sum,i+1,n,count);

Base Case: We run out of elements:

Here we have to decide whether the subset we have made this far should be counted(sum==0) or not(sum!=0), thus
if(i==n){ if(sum==0){ count++; } return; }

#7

would both the statements be executed simultaneously?

#8

or the first statement would reach base case then the compiler would compile the second statement

#9

https://ide.codingblocks.com/s/199819 i have written my doubt as comments

#10

and what would happen if i do that

#11

What was said in video, is correct.

#12

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