fenwick tree with range updates

Author: DASHAN JOT SINGH

Data Structures/Fenwick Tree/Fenwick_tree_range_updates.cpp

@@ -0,0 +1,92 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+#define ll long long int
+#define re1(x) scanf("%lld",&x)
+#define re2(x,y) scanf("%lld%lld",&x,&y)
+#define re3(x,y,z) scanf("%lld%lld%lld",&x,&y,&z)
+#define pr(x) printf("%lld\n",x);
+#define pb push_back
+#define mp make_pair
+ll n,u,q;
+ll arr[10010];
+ll BIT_1[10020];
+ll BIT_2[10020];
+void update1(ll index,ll val){
+	index+=1;
+	while(index<=n){
+		BIT_1[index]+=val;
+		index+=(index&(-index));
+		//go to next element to be updated
+	}
+}
+ll query1(ll index){
+	index+=1;
+	// as bittree has one extra element
+	ll sum=0;
+	while(index>0){
+		sum+=BIT_1[index];
+		index-=(index&(-index));
+	}
+	return sum;
+}
+void update2(ll index,ll val){
+	index+=1;
+	while(index<=n){
+		BIT_2[index]+=val;
+		index+=(index&(-index));
+		//go to next element to be updated
+	}
+}
+ll query2(ll index){
+	index+=1;
+	// as bittree has one extra element
+	ll sum=0;
+	while(index>0){
+		sum+=BIT_2[index];
+		index-=(index&(-index));
+	}
+	return sum;
+}
+void update_r(ll l,ll r,ll val){
+	update1(l,val);
+	update1(r+1,-val);
+	update2(l,val*(l-1));
+	update2(r+1,-val*r);
+}
+ll sum(ll x){
+	return ((query1(x)*x)-query2(x));
+}
+ll range_sum(ll l,ll r){
+	return sum(r)-sum(l-1);
+}
+int main(){
+	ll t;
+	re1(t);
+	while(t--){
+		re2(n,u);
+		for(ll i=0;i<n;i+=1){
+			arr[i]=0;
+		}
+		for(ll i=0;i<=n;i+=1){
+			BIT_1[i]=0;
+			BIT_2[i]=0;
+		}
+		for(ll i=0;i<u;i+=1){
+			ll l,r,val;
+			re3(l,r,val);
+			update_r(l,r,val);
+		}
+		re1(q);
+		for(ll i=0;i<q;i+=1){
+			ll xx;
+			re1(xx);
+			//xx-=1;
+			ll yy=range_sum(0,xx-1);
+			ll xx1=range_sum(0,xx);
+			ll ans=xx1-yy;
+			pr(ans);
+		}
+	}
+	return 0;
+}