HackerEarth- Xsquare And Two Arrays (Dynamic Problem Solution)

Xsquare And Two Arrays (HackerEarth)

Dynamic Programming, Easy;

Solution:-

#include<iostream>

using namespace std;

#define MAX 1000010

#define ll long long

#define f(i,a,b) for(int i=a;i<=b;i++)

#define fd(i,a,b) for(int i=a;i<=b;i+=2)

ll arrA[MAX],arrB[MAX];

ll cal_sum(int start,int left,int right)

{

    if(start==1)

    {

        if(left%2)

            return arrA[right]-arrA[left-1];

        else

            return arrB[right]-arrB[left-1];

    }

    else

    {

        if(left%2==0)

            return arrA[right]-arrA[left-1];

        else

            return arrB[right]-arrB[left-1];

    }

}

int main()

{

    int N,Q;

    cin>>N>>Q;

    int i,j;

    arrA[0]=arrB[0]=0;

    f(i,1,N)

        cin>>arrA[i];

    f(i,1,N)

        cin>>arrB[i];

    fd(i,2,N)

        swap(arrA[i],arrB[i]);

    f(i,2,N)

    {

        arrA[i]+=arrA[i-1];

        arrB[i]+=arrB[i-1];

    }

    int start,left,right;

    f(i,0,Q-1)

    {

        cin>>start>>left>>right;

        cout<<cal_sum(start,left,right)<<endl;

    }

    return 0;

}