Update segment_tree.cpp

1 files changed, 1 insertions, 1 deletions

diff --git a/Data Structures/segment_tree.cpp b/Data Structures/segment_tree.cpp
index c7b058f..d1974b8 100644
--- a/Data Structures/segment_tree.cpp
+++ b/Data Structures/segment_tree.cpp
@@ -17,7 +17,7 @@ void update(int x, T v, int l = 0, int r = -1, int n = 1) {
 void update(int a, int b, int v, int l = 0, int r = -1, int n = 1) {
 	if (r == -1) r = N - 1;
 	push(l, r, n);
-	if (l > b || r < a) return;
+	if (l > r || l > b || r < a) return;
 	if (l >= a && r <= b) {
 		tmp[n] += v;
 		push(l, r, n);