made lazy propagation template general and not problem specific

Data structures/Lazy_propagation_range_sum_update.cpp

@@ -3,7 +3,7 @@ vector<ll> tree(4*N), lazy(4*N);
 
 ll merge( ll left, ll right){
 	ll tmp;
-	tmp = left + right ;
+	// build temp from left and right according to quest
 	return tmp;
 }
 
@@ -12,24 +12,28 @@ void ulazy( ll pos, ll lo, ll hi, ll qlo, ll qhi, ll val){
 	ll l = (pos<<1)+1, r = l+1;
 
 	if( lazy[pos] ){	// if there are pending updates to current node
-		tree[pos] += (hi-lo+1)*lazy[pos];	
+
+		// Here, add lazy[pos] effect to tree[pos](Current node)
 
+		// lazy propagation to child nodes if they exist
 		if( lo != hi ){		
-			lazy[l] += lazy[pos];
-			lazy[r] += lazy[pos];
+
 		}	
-
+
+		// clear lazy[pos]
 		lazy[pos] = 0;
 	}	
 
 	if( lo > hi || lo > qhi || hi < qlo )
 		return;
 
 	if( qlo <= lo && hi <= qhi ){	// queried segment totally overlaps the current range of function
-		tree[pos] += (hi-lo+1)*val;
+
+		// add effect of entire range to tree[pos]
+
+		// Add lazy to child nodes if they exist
 		if( lo != hi ){
-			lazy[l] += val;
-			lazy[r] += val;
+
 		} 		
 		return;
 	}	
@@ -51,11 +55,11 @@ ll qlazy( ll pos, ll lo, ll hi, ll qlo, ll qhi){
 		return 0;
 
 	if( lazy[pos] ){	// if there are pending updates to current node
-		tree[pos] += (hi-lo+1)*lazy[pos];	
+		// Here, add lazy[pos] effect to tree[pos](Current node)
 
+		// lazy propagation to child nodes if they exist	
 		if( lo != hi ){		
-			lazy[l] += lazy[pos];
-			lazy[r] += lazy[pos];
+
 		}	
 
 		lazy[pos] = 0;

Data structures/lazy_propagation.cpp

@@ -0,0 +1,93 @@
+vector<ll> v(N);
+vector<ll> tree(4*N), lazy(4*N);
+
+ll merge( ll left, ll right){
+	ll tmp;
+	// build temp from left and right according to quest
+	return tmp;
+}
+
+void ulazy( ll pos, ll lo, ll hi, ll qlo, ll qhi, ll val){
+
+	ll l = (pos<<1)+1, r = l+1;
+
+	if( lazy[pos] ){	// if there are pending updates to current node
+
+		// Here, add lazy[pos] effect to tree[pos](Current node)
+
+		// lazy propagation to child nodes if they exist
+		if( lo != hi ){		
+
+		}	
+
+		// clear lazy[pos]
+		lazy[pos] = 0;
+	}	
+
+	if( lo > hi || lo > qhi || hi < qlo )
+		return;
+
+	if( qlo <= lo && hi <= qhi ){	// queried segment totally overlaps the current range of function
+
+		// add effect of entire range to tree[pos]
+
+		// Add lazy to child nodes if they exist
+		if( lo != hi ){
+
+		} 		
+		return;
+	}	
+
+	ll mid = mid(lo,hi);
+
+	ulazy( l, lo, mid, qlo, qhi, val);
+	ulazy( r, mid+1, hi, qlo, qhi, val);
+
+	tree[pos] = merge( tree[l], tree[r] );
+
+}
+
+ll qlazy( ll pos, ll lo, ll hi, ll qlo, ll qhi){
+
+	ll l = (pos<<1)+1, r = l+1;
+
+	if( lo > qhi || lo > hi || hi < qlo	)
+		return 0;
+
+	if( lazy[pos] ){	// if there are pending updates to current node
+		// Here, add lazy[pos] effect to tree[pos](Current node)
+
+		// lazy propagation to child nodes if they exist	
+		if( lo != hi ){		
+
+		}	
+
+		lazy[pos] = 0;
+	}
+
+	if( qlo <= lo && qhi >= hi )	// the segment of current node is completely inside queried range
+		return tree[pos];
+
+	ll mid = mid( lo , hi );
+
+	if( qlo > mid)
+		return qlazy( r, mid+1, hi, qlo, qhi);
+	else if( qhi <= mid)
+		return qlazy( l, lo, mid, qlo, qhi);
+
+	ll left = qlazy( l, lo, mid, qlo, qhi);
+	ll right = qlazy( r, mid+1, hi, qlo, qhi);	
+
+	return merge( left, right);
+}
+
+
+/*	
+	BEFORE EVERY TEST CASE
+	
+	lp(i, 4*n + 1){
+			lazy[i] = 0;
+			tree[i] = 0;	
+	}
+
+*/