From fea817cc878196e37840d969735ca66c71858523 Mon Sep 17 00:00:00 2001
From: vagi2706 <115474543+vagi2706@users.noreply.github.com>
Date: Mon, 10 Oct 2022 20:27:03 +0530
Subject: [PATCH] Create Fenwick.cpp

Range sum and range query support added
---
 Algorithm/Fenwick.cpp | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 Algorithm/Fenwick.cpp

diff --git a/Algorithm/Fenwick.cpp b/Algorithm/Fenwick.cpp
new file mode 100644
index 0000000..c340093
--- /dev/null
+++ b/Algorithm/Fenwick.cpp
@@ -0,0 +1,41 @@
+//------------fenwick--------------
+template<typename T>
+struct Fenwick{
+// Declaration - Fenwick<ll> f(n);
+private:
+    ll n;
+    vector<T> bit[2];
+public:
+    Fenwick(){
+    }
+    Fenwick(ll maxn){
+        n = maxn;
+        bit[0] = vector<T>(n+100,0);
+        bit[1] = vector<T>(n+100,0);
+    }
+    void add(ll tree, ll idx, T x){
+        while(idx<=n){
+            bit[tree][idx]+=x, idx+= (idx & (-idx));
+        }
+    }
+    void range_add(ll l, ll r, T x){
+        add(0,l,x);
+        add(0,r+1,-x);
+        add(1,l,x*(l-1));
+        add(1,r+1,-x*r);
+    }
+    T sum(ll tree, ll idx){
+        T total = 0;
+        while(idx>0){
+            total+=bit[tree][idx];
+            idx -= (idx & (-idx));
+        }
+        return total;
+    }
+    T prefix_sum(ll idx){
+        return sum(0,idx)*idx - sum(1,idx);
+    }
+    T range_sum(ll l, ll r){
+        return prefix_sum(r) - prefix_sum(l-1);
+    }
+};