From 28cfa2513b78f548e25a1d71f4c9ba11ce877e93 Mon Sep 17 00:00:00 2001
From: Ta180m <ta180m@gmail.com>
Date: Wed, 17 Jun 2020 13:26:00 -0500
Subject: [PATCH] Update dynamic_segment_tree_2d.cpp

---
 Data Structures/dynamic_segment_tree_2d.cpp | 36 ++++++++-------------
 1 file changed, 13 insertions(+), 23 deletions(-)

diff --git a/Data Structures/dynamic_segment_tree_2d.cpp b/Data Structures/dynamic_segment_tree_2d.cpp
index 430447d..c19a488 100644
--- a/Data Structures/dynamic_segment_tree_2d.cpp	
+++ b/Data Structures/dynamic_segment_tree_2d.cpp	
@@ -1,51 +1,41 @@
 struct y_node {
 	int val;
 	y_node* c[2];
-	y_node() {
-		val = 0;
-		c[0] = c[1] = 0;
-	}
-	y_node* get_c(int i) {
-		return (!c[i] ? c[i] = new y_node : c[i]);
-	}
-	void update(int y, int v, int l = 0, int r = MAXN) {
-		if (l == r) val = v;
+	y_node() { val = 0; c[0] = c[1] = 0; }
+	y_node* get_c(int i) { return (!c[i] ? c[i] = new y_node : c[i]); }
+	void update(int y, int v, int l = -1, int r = MAXN) {
+		if (l == r) val += v;
 		else {
 			int m = (l + r) >> 1;
 			y <= m ? get_c(0)->update(y, v, l, m) : get_c(1)->update(y, v, m + 1, r);
-			val = max((c[0] ? c[0]->val : 0), (c[1] ? c[1]->val : 0));
+			val = (c[0] ? c[0]->val : 0) + (c[1] ? c[1]->val : 0);
 		}
 	}
-	int query(int yl, int yr, int l = 0, int r = MAXN) {
+	int query(int yl, int yr, int l = -1, int r = MAXN) {
 		if (yl > r || yr < l) return 0;
 		if (yl <= l && yr >= r) return val;
 		int m = (l + r) >> 1;
-		return max((c[0] ? c[0]->query(yl, yr, l, m) : 0), (c[1] ? c[1]->query(yl, yr, m + 1, r) : 0));
+		return (c[0] ? c[0]->query(yl, yr, l, m) : 0) + (c[1] ? c[1]->query(yl, yr, m + 1, r) : 0);
 	}
 };
 
 struct x_node {
 	y_node seg;
 	x_node* c[2];
-	x_node() {
-		c[0] = c[1] = 0;
-	}
-	x_node* get_c(int i) {
-		return (!c[i] ? c[i] = new x_node : c[i]);
-	}
-	void update(int x, int y, int v, int l = 0, int r = MAXN) {
+	x_node() { c[0] = c[1] = 0;}
+	x_node* get_c(int i) { return (!c[i] ? c[i] = new x_node : c[i]); }
+	void update(int x, int y, int v, int l = -1, int r = MAXN) {
 		if (l == r) seg.update(y, v);
 		else {
 			int m = (l + r) >> 1;
 			x <= m ? get_c(0)->update(x, y, v, l, m) : get_c(1)->update(x, y, v, m + 1, r);
-			int tmp = max((c[0] ? c[0]->seg.query(y, y) : 0), (c[1] ? c[1]->seg.query(y, y) : 0));
-			seg.update(y, tmp);
+			seg.update(y, (c[0] ? c[0]->seg.query(y, y) : 0) + (c[1] ? c[1]->seg.query(y, y) : 0));
 		}
 	}
-	int query(int xl, int xr, int yl, int yr, int l = 0, int r = MAXN) {
+	int query(int xl, int xr, int yl, int yr, int l = -1, int r = MAXN) {
 		if (xl > r || xr < l) return 0;
 		if (xl <= l && xr >= r) return seg.query(yl, yr);
 		int m = (l + r) >> 1;
-		return max((c[0] ? c[0]->query(xl, xr, yl, yr, l, m) : 0), (c[1] ? c[1]->query(xl, xr, yl, yr, m + 1, r) : 0));
+		return (c[0] ? c[0]->query(xl, xr, yl, yr, l, m) : 0) + (c[1] ? c[1]->query(xl, xr, yl, yr, m + 1, r) : 0);
 	}
 } root;
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