Create Lazy Propagation

Lazy Propagation using Binary Indexed Tree.

Author: cyclades1

Lazy Propagation

@@ -0,0 +1,104 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+#define intmax 1000000
+#define endl "\n"
+#define add(a,b) a+b
+
+typedef long long ll ;
+
+ll tree[intmax];
+ll lazy[intmax];
+
+void update(ll node , ll start , ll end, ll l ,ll r, ll value)
+{
+
+
+    if(lazy[node]!= 0)
+    {
+        tree[node]+= (end-start +1)*lazy[node];
+        if(start != end)
+        {
+            lazy[node*2]+= lazy[node];
+            lazy[node*2+1]+= lazy[node];
+        }
+        lazy[node]=0;
+    }
+     if(start>end || r <start || l>end)
+        return;
+    if(l<= start && end<= r)
+    {
+        tree[node]+=(end-start +1) *value;
+        if(start != end)
+        {
+            lazy[node*2]+=value;
+            lazy[node*2+1]+= value;
+        }
+        return;
+    }
+    ll mid = (start+end)/2;
+    update(node*2,start,mid,l,r,value);
+    update(node*2+1,mid+1,end,l, r,value);
+    tree[node]=tree[node*2]+tree[node*2+1];
+}
+
+ll query (ll node , ll start, ll end , ll l, ll r)
+{
+    if(r<start || l> end ||start >end)
+    {
+        return 0;
+    }
+    if(lazy[node]!= 0)
+    {
+        tree[node]+=(end-start+1)*lazy[node];
+        if(start != end)
+        {
+            lazy[node*2]+= lazy[node];
+            lazy[node*2+1]+=lazy[node];
+        }
+        lazy[node]= 0;
+    }
+    if(l<= start && end <= r)
+    {
+        return tree[node];
+    }
+    ll mid = (start+end)/2;
+    ll p1 = query(2*node, start ,mid , l, r);
+    ll p2 = query(2*node +1, mid +1 , end, l , r);
+    return (add(p1,p2));
+}
+
+int main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+    cout.tie(NULL);
+    ll t;
+    cin >> t;
+
+    while(t--){
+    memset(tree, 0, sizeof(tree));
+    memset(lazy, 0, sizeof(lazy));
+    ll n , q;
+    cin >> n>> q;
+    while(q--)
+    {
+
+        int ch ;
+        cin >> ch;
+        if(ch == 1)
+        {
+            ll l ,r;
+            cin >> l >>r;
+            cout<<query(1,0,n-1,l-1,r-1)<<endl;
+        }
+        else
+        {
+            ll l  , r, value;
+            cin >> l>>r>>value;
+            update(1,0,n-1,l-1, r-1,value);
+        }
+    }
+    }
+    return 0;
+}