https://cses.fi/problemset/task/1735
I have written the following code for the question above…
I couldn’t understand where my code goes wrong kindly please help me in debugging this code
Thanks 
#include<bits/stdc++.h>
using namespace std;
#define ll long long int
void lazyupdates(ll a[],ll lazy1[],ll lazy2[],ll l, ll r,ll i)
{
if(lazy1[i])
{
a[i] += (lazy1[i]*(r-l+1));
if(l!=r)
{
lazy1[2*i+1] += lazy1[i];
lazy1[2*i+2] += lazy1[i];
}
lazy1[i] = 0;
}
if(lazy2[i])
{
a[i] = (lazy2[i]*(r-l+1));
if(l!=r)
{
lazy2[2*i+1] = lazy2[i];lazy1[2*i+1] = 0;
lazy2[2*i+2] = lazy2[i];lazy1[2*i+2] = 0;
}
lazy2[i] = 0;
}
}
void BuildTree(ll a[],ll l,ll r,ll i=0)
{
if(l==r)cin>>a[i];
else
{
ll mid = l+(r-l)/2;
BuildTree(a,l,mid,2*i+1);
BuildTree(a,mid+1,r,2*i+2);
a[i] = a[2*i+1] + a[2*i+2];
}
}
ll getsum(ll a[],ll lazy1[],ll lazy2[],ll ql,ll qr,ll l,ll r,ll i=0)
{
lazyupdates(a,lazy1,lazy2,l,r,i);
if(l>qr || r<ql || l>r)return 0;
if(l>=ql && r<=qr)return a[i];
else
{
ll mid=l+(r-l)/2;
return getsum(a,lazy1,lazy2,ql,qr,l,mid,2*i+1)+getsum(a,lazy1,lazy2,ql,qr,mid+1,r,2*i+2);
}
}
void update1(ll a[],ll lazy1[],ll lazy2[],ll ql,ll qr,ll l,ll r,ll x,ll i=0)
{
lazyupdates(a,lazy1,lazy2,l,r,i);
if(l>qr || r<ql || l>r)return;
else if(l>=ql && r<=qr)
{
a[i] += ((r-l+1)*x);
if(l!=r)
{
ll mid = l+(r-l)/2;
lazyupdates(a,lazy1,lazy2,l,mid,2*i+1);lazy1[2*i+1] += x;
lazyupdates(a,lazy1,lazy2,mid+1,r,2*i+2);lazy1[2*i+2] += x;
}
}
else
{
ll mid = l+(r-l)/2;
update1(a,lazy1,lazy2,ql,qr,l,mid,x,2*i+1);
update1(a,lazy1,lazy2,ql,qr,mid+1,r,x,2*i+2);
a[i] = a[2*i+1] + a[2*i+2];
}
}
void update2(ll a[],ll lazy1[],ll lazy2[],ll ql,ll qr,ll l,ll r,ll x,ll i=0)
{
lazyupdates(a,lazy1,lazy2,l,r,i);
if(l>qr || r<ql || l>r)return;
else if(l>=ql && r<=qr)
{
a[i] = (r-l+1)*x;
if(l!=r)
{
ll mid = l+(r-l)/2;
lazyupdates(a,lazy1,lazy2,l,mid,2*i+1);
lazyupdates(a,lazy1,lazy2,mid+1,r,2*i+2);
lazy2[2*i+1] = lazy2[2*i+2] = x;
lazy1[2*i+1] = lazy1[2*i+2] = 0;
}
}
else
{
ll mid=l+(r-l)/2;
update2(a,lazy1,lazy2,ql,qr,l,mid,x,2*i+1);
update2(a,lazy1,lazy2,ql,qr,mid+1,r,x,2*i+2);
a[i] = a[2*i+1] + a[2*i+2];
}
}
int main()
{
ll n,q,k,ql,qr,x;cin>>n>>q;
ll a[4*n]={0},lazy1[4*n]={0},lazy2[4*n]={0};
BuildTree(a,0,n-1);
while(q--)
{
cin>>k>>ql>>qr;ql--;qr--;
if(k==1)
{
cin>>x;
update1(a,lazy1,lazy2,ql,qr,0,n-1,x);
}
else if(k==2)
{
cin>>x;
update2(a,lazy1,lazy2,ql,qr,0,n-1,x);
}
else cout<<getsum(a,lazy1,lazy2,ql,qr,0,n-1)<<"\n";
}
}