TheAlgorithms-C-Plus-Plus/Range queries/segTree.cpp

#include <bits/stdc++.h>
#define MAX 4000000
using namespace std;
typedef long long ll;
void ConsTree(ll arr[],ll segtree[],ll low,ll high,ll pos)
{
	if(low == high)
	{
		segtree[pos] = arr[low];
		return;
	}
	ll mid = (low+high)/2;
	ConsTree(arr,segtree,low,mid,2*pos+1);
	ConsTree(arr,segtree,mid+1,high,2*pos+2);
	segtree[pos] = segtree[2*pos+1] + segtree[2*pos+2];
}
ll query(ll segtree[],ll lazy[],ll qlow,ll qhigh,ll low,ll high,ll pos)
{
	if(low > high)
		return 0;
	if(qlow>high || qhigh<low)
		return 0;
	if(lazy[pos] != 0)
	{
		segtree[pos] += lazy[pos]*(high-low+1);
		if(low != high)
		{
			lazy[2*pos+1] += lazy[pos];
			lazy[2*pos+2] += lazy[pos];
		}
		lazy[pos] = 0;
	}
	if(qlow<=low && qhigh>=high)
		return segtree[pos];
		ll mid = (low+high)/2;
	return query(segtree,lazy,qlow,qhigh,low,mid,2*pos+1) + query(segtree,lazy,qlow,qhigh,mid+1,high,2*pos+2);
}
void update(ll segtree[],ll lazy[],ll start,ll end,ll delta,ll low,ll high,ll pos)
{
	if(low>high)
		return;
	if(lazy[pos] != 0)
	{
		segtree[pos] += lazy[pos]*(high-low+1);
		if(low!=high)
		{
			lazy[2*pos+1] += lazy[pos];
			lazy[2*pos+2] += lazy[pos];
		}
		lazy[pos] = 0;
	}
	if(start > high || end < low)
		return;
	if(start <= low && end >= high)
	{
		segtree[pos] += delta*(high-low+1);
		if(low != high)
		{
			lazy[2*pos+1] += delta;
			lazy[2*pos+2] += delta;
		}
		return;
	}
	ll mid = (low+high)/2;
	update(segtree,lazy,start,end,delta,low,mid,2*pos+1);
	update(segtree,lazy,start,end,delta,mid+1,high,2*pos+2);
	segtree[pos] = segtree[2*pos+1] + segtree[2*pos+2];
}
int main() {
		ll n,c;
		scanf("%lld %lld",&n,&c);
		ll arr[n]={0},p,q,v,choice;
		ll segtree[MAX],lazy[MAX]={0};
		ConsTree(arr,segtree,0,n-1,0);
		while(c--)
		{
			scanf("%lld",&choice);
			if(choice == 0)
			{
				scanf("%lld %lld %lld",&p,&q,&v);
				update(segtree,lazy,p-1,q-1,v,0,n-1,0);
			}
			else
			{
				scanf("%lld %lld",&p,&q);
				printf("%lld\n",query(segtree,lazy,p-1,q-1,0,n-1,0));
			}
		}
	return 0;
}