Merge pull request matthewsamuel95#919 from Es7evam/ImplicitSegTree

Add Implicit Segment Tree C++ code

Author: matthewsamuel95

Data Structures/Segment Tree/ImplicitSegmentTree.cpp

@@ -0,0 +1,83 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+#define pb push_back
+#define mk make_pair
+#define fi first
+#define se second
+
+typedef long long ll;
+typedef pair<int, int> ii;
+const int INF = 0x3f3f3f3f;
+const double PI = acos(-1.0);
+
+struct node {
+	node *l, *r;
+	ll val, lazy;
+
+	node () {
+		l = r = 0;
+		val = lazy = 0;
+	}
+};
+
+void prop (node *at, int i, int j) {
+	at->val += at->lazy * (j - i + 1);
+
+	if (i != j) {
+		if (!at->l)	at->l = new node();
+		if (!at->r)	at->r = new node();
+
+		at->l->lazy += at->lazy;
+		at->r->lazy += at->lazy;
+	}
+
+	at->lazy = 0;
+}
+
+ll query (node *at, int i, int j, int a, int b, int val) {
+	prop (at, i, j);
+	if (j < a or i > b)	return 0;
+
+	if (i >= a and j <= b) {
+		at->lazy += val;
+		prop (at, i, j);
+		return at->val;
+	} else {
+		int mid = (i + j)>>1;
+
+		if (!at->l)	at->l = new node();
+		if (!at->r) at->r = new node();
+
+		ll L = query (at->l, i, mid, a, b, val);
+		ll R = query (at->r, mid + 1, j, a, b, val);
+		at->val = at->l->val + at->r->val;
+		return L + R;
+	}
+}
+
+int main (void) {
+	ios_base::sync_with_stdio(false);
+
+	int T;	cin >> T;
+	while (T--) {
+		node *root = new node();
+
+		int n, q;	cin >> n >> q;
+
+		while (q--) {
+			int c, l, r;	cin >> c >> l >> r;
+			l--;	r--;
+			if (l > r)	swap (l, r);
+			if (c == 0) {
+				int v;	cin >> v;
+				query (root, 0, n - 1, l, r, v);
+			} else {
+				cout << query (root, 0, n - 1, l, r, 0) << endl;
+			}
+		}
+	}
+
+	return 0;
+}