golf

lrvideckis · lrvideckis · commit 673622fe0b5d · 2025-04-23T07:59:20.000-06:00
diff --git a/library/trees/edge_cd.hpp b/library/trees/edge_cd.hpp
@@ -37,9 +37,9 @@ template<class F, class G> struct edge_cd {
         if (cent != -1) return cent;
         siz[v] += siz[u];
       }
-    if (p == -1) return v;
-    return 2 * siz[v] > m     ? siz[p] = m + 1 - siz[v],
-                            v : -1;
+    return 2 * siz[v] > m
+           ? p >= 0 && (siz[p] = m + 1 - siz[v]),
+           v : -1;
   }
   void dfs(int v, int m) {
     if (m < 2) return;

Original file line number	Diff line number	Diff line change
`@@ -37,9 +37,9 @@ template<class F, class G> struct edge_cd {`
`37`	`37`	`if (cent != -1) return cent;`
`38`	`38`	`siz[v] += siz[u];`
`39`	`39`	`}`
`40`		`- if (p == -1) return v;`
`41`		`- return 2 * siz[v] > m ? siz[p] = m + 1 - siz[v],`
`42`		`- v : -1;`
	`40`	`+ return 2 * siz[v] > m`
	`41`	`+ ? p >= 0 && (siz[p] = m + 1 - siz[v]),`
	`42`	`+ v : -1;`
`43`	`43`	`}`
`44`	`44`	`void dfs(int v, int m) {`
`45`	`45`	`if (m < 2) return;`