Code of maximum subarray 2

#1

#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;
}

#2

@jindaldivish
hello divish,
what issue u r facing?

#3

what will happen when the nested for loop will execute and value of i=0

#4

When i=0 cumsum[i-1]; will be cumsum[-1]. The compiler automatically assigns cumsum[-1] as 0 and the code runs correctly without error. You can check that on your own.

Doubt on statement currentsum=cumsum[j]-cumsum[i-1];
Value of cumsum[-1]
Loop boundary not clear
#5

but we know that we can’t access negaitve indices of the array , then how can compiler assigns cumsum[-1]=0

#6

Ye you are correct and you should prevent using negative indexes in C++ but newer versions of compiler supports and does not throw an error.
Check this https://ide.codingblocks.com/s/200734

#7

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