Subset sum possible or not

#1

plz check this code is showing wrong ans …we have to print yes or no if we can obtain a given sum by choosing a subset of given array or not…
plz correct this code and explain as well…

#2

@S19LPPP0202

bool subset(int n,int a[],int x,int i){
if(x==0){ //this would come first
    return true;
}

if(i==n){
    return false;
}

if(x<0){
    return false;
}

bool flag=subset(n,a,x-a[i],i+1)||subset(n,a,x,i+1); // don't do ++i , as it changes the value of i in second case as well.
return flag;

}
Note: you have to memoize this also.

#3

why will x==0 come first??plz explain…

#4

will this code work for negative numbers in an array as well??

#5

because if i==n and x was zero then you will return false, but x = 0 then you have to return true.
yes it will work for negative number.

#6

plz reply to this doubt of mine as well.this is unresolved…

click on this link and plz reply to this doubt of mine as well…
it would be really helpful

#7

Only you can understand your approach better.
and also your approach, may not work for all cases.
Try to think/debug yourself only that will help you grow and improve.

#8

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