Merge pull request #1213 from akoutian/patch-1

jakobkogler · web-flow · commit 1af10d5744ba · 2024-01-28T20:50:32.000+01:00
Add "build" function to segment_tree.md
diff --git a/src/data_structures/segment_tree.md b/src/data_structures/segment_tree.md
@@ -805,6 +805,17 @@ Before traversing to a child vertex, we call $\text{push}$ and propagate the val
 We have to do this in both the $\text{update}$ function and the $\text{query}$ function.
 
 ```cpp
+void build(int a[], int v, int tl, int tr) {
+    if (tl == tr) {
+        t[v] = a[tl];
+    } else {
+        int tm = (tl + tr) / 2;
+        build(a, v*2, tl, tm);
+        build(a, v*2+1, tm+1, tr);
+        t[v] = max(t[v*2], t[v*2 + 1]);
+    }
+}
+
 void push(int v) {
     t[v*2] += lazy[v];
     lazy[v*2] += lazy[v];
