Getting WA in BENDSP2

CodeChef: Practical coding for everyone why is this WA’ing?? It calculates number of odd and even terms and straight away adds it to total odd and even value, pls guide

Can the sum overflow?

It might, still getting WA CodeChef: Practical coding for everyone

After so long time, found some test case where your code fails.

Input:

5
9 10 1 4 10
8
2 
2 
1 2 2 1
3 
3 
3 
1 5 5 5
3

Expected Output:

20
20
15
15
15
15

Your Output

20
20
14
14
14
14

Your Code, ACfied.

CPP Code
#include <bits/stdc++.h>
using namespace std;
#define int long long
signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int t=1,n,a,odd=0,even=0,q,l,r,x,terms; 
  //  cin >> t; 
    while (t--){
        cin >> n;
        for (int i = 1; i <= n;i++){
            cin >> a;
            if (i & 1){
                odd += a;
            }
            else {
                even += a;
            }
        }
        cin >> q;
        for (int i = 0; i < q; i++){
            cin >> a;
            if (a==1){
                cin >> l >> r >> x;
                if (((l&1)==0) && ((r&1)==0)){
                    terms = (r-l+1);
                    even += (((terms/2)+1)*x);
                    odd += ((terms/2)*x);
                }
                else if ((l&1) && (r&1)) {
                    terms = (r-l+1);
                    odd += (((terms/2)+1)*x);
                    even += ((terms/2)*x);
                }
                else {
                    terms = (r-l+1);
                    odd += ((terms/2)*x);
                    even += ((terms/2)*x);
                }
            }
            else if (a==2){
                cout << odd << "\n";
            }
            else {
                cout << even << "\n";
            }
        }
    }
    return 0;
}

Lots of thanks!!! Why was my WA’ing, CodeChef: Practical coding for everyone this was the corrected code for the test case you submitted, what have you changed to AC’ify my code other than changing if’s to else if’s and else’s, or is that it.