Fix segment trees

Signed-off-by: Bruno Freitas Tissei <bft15@inf.ufpr.br>

structure/lazy_segment_tree.cpp

@@ -8,7 +8,7 @@
  * Complexity (Space): O(n)
  */
 
-int N, tree[2 * MAX], lazy[2 * MAX], v[MAX];
+int N, tree[4 * MAX], lazy[4 * MAX], v[MAX];
 
 // Build tree with elements from v
 void build_tree(int node = 1, int a = 0, int b = N) {
@@ -63,7 +63,7 @@ void update_tree(int i, int j, int val, int node = 1, int a = 0, int b = N) {
   tree[node] = tree[node * 2] + tree[node * 2 + 1];
 }
 
-// Return sum from i to j
+// Return sum of [i,j]
 int query_tree(int i, int j, int node = 1, int a = 0, int b = N) {
   if (a > b || a > j || b < i)
     return 0;

structure/segment_tree.cpp

@@ -8,7 +8,7 @@
  * Complexity (Space): O(n)
  */
 
-int N, tree[2 * MAX], v[MAX];
+int N, tree[4 * MAX], v[MAX];
 
 // Build tree with elements from v
 void build_tree(int node = 1, int a = 0, int b = N) {
@@ -42,7 +42,7 @@ void update_tree(int idx, int val, int node = 1, int a = 0, int b = N) {
   tree[node] = tree[node * 2] + tree[node * 2 + 1];
 }
 
-// Return sum from i to j
+// Return sum of [i,j]
 int query_tree(int i, int j, int node = 1, int a = 0, int b = N) {
   if (a > b || a > j || b < i)
     return 0;