Nested for loop problem when i=0 and j=0

#1

what is the value of cumsum[-1] when i=0.

#2

@jindaldivish you cannot access negative indices of an array.

#3

but we have accessed in the algorithms as we have written currentsum=cumsum[j]-cumsum[i-1]
and here i =0 for eg;

#4

#include
using namespace std;
int main()
{
int n,current_sum=0,maximum_sum=0,left,right;
cin>>n;
int a[1000];
cin>>a[0];
int cumsum[1000];
cumsum[0]=a[0];
for(int i=1;i<n;i++)
{
cin>>a[i];
cumsum[i]=cumsum[i-1]+a[i];
}
for(int i=0;i<n;i++)
{
for(int j=i;j<n;j++)
{
current_sum=cumsum[j]-cumsum[i-1];
if(current_sum>maximum_sum)
{
maximum_sum=current_sum;
left=i;
right=j;
}
}
}
cout<<“maximum sum is: “<<maximum_sum<<endl;
for(int i=left;i<=right;i++)
cout<<a[i]<<”,”;
return 0;
}
what will happen when the nested for loops will execute for the first time with i=0 and j=0 because we dont have the value of cumsum[-1]

#5

@jindaldivish
hello divish,
we cannot access negative index . it will give runtime error.
so when i=0 and j=0 ur current_sum=cumsum[j] only ( u need to handle this case separately)

#6

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