code style

1 files changed, 24 insertions, 20 deletions

diff --git a/content/graph/reroot.cpp b/content/graph/reroot.cpp
index 59fea94..6c9551e 100644
--- a/content/graph/reroot.cpp
+++ b/content/graph/reroot.cpp
@@ -1,47 +1,51 @@
-// input: undirected (un)weighted tree as
-//        adjacency list containing pair<neighbour,weight>s
-//        (To remove weights, remove every "w" and fix errors)
 // output[r] = dp[r], where dp[v] :=
-//  fin(Sum_{child c of v, regarding root r} from_child( dp[c] ))
+//  fin(Sum_{child c of v, regarding root r} fromChild( dp[c] ))
+
+// To remove weights, remove every "w" and "W" and fix errors
 struct Reroot {
-  using D = todo; // dp value
-  using A = todo (often D); // value from a vertex's child(ren)
+  using D = /todo/; // dp value
+  using A = /todo/ (often D); // value from a vertex's child(ren)
                             // (A,agg,e) commutative monoid
 
-  A e = todo;
-  A from_child(z v, z c, auto w, D dp_c) { todo }
-  static A agg(A a, A b) { todo }
-  D fin(z v, A chils_agg) { todo }
+  A e = /todo/;
+  A fromChild(int v, int c, auto w, D dp_c) { /todo/ }
+  static A agg(A a, A b) { /todo/ }
+  D fin(int v, A chilsAgg) { /todo/ }
 
   vector<D> dp;
 
-  D dfs0(z v, z p, auto& g) {
+  D dfs0(auto& g, int v, int from = -1) {
     A ca = e;
-    for (auto [c, w] : g[v]) if(c-p) {
-      ca = agg(ca, from_child(v, c, w, dfs0(c, v, g)));
+    for (auto [c, w] : g[v]) {
+      if (c == from) continue;
+      ca = agg(ca, fromChild(v, c, w, dfs0(c, v, g)));
     }
     return dp[v] = fin(v, ca);
   }
-  void dfs1(z v, z p, auto& g) {
+
+  void dfs1(auto& g, int v, int from = -1) {
     vector ps = {e};
     for (auto [c, w] : g[v]) {
-      ps.push_back(from_child(v, c, w, dp[c]));
+      ps.push_back(fromChild(v, c, w, dp[c]));
     }
     auto ss = ps;
     exclusive_scan(ps.begin(), ps.end(), ps.begin(), e, agg);
     exclusive_scan(ss.rbegin(),ss.rend(),ss.rbegin(),e, agg);
-    z i = 0;
-    for (auto [c, w] : g[v]) if(++i, c-p) {
+    int i = 0;
+    for (auto [c, w] : g[v]) {
+      ++i;
+      if (c == from) continue;
       dp[v] = fin(v, agg(ss[i], ps[i]));
       dfs1(c, v, g);
     }
     dp[v] = fin(v, ss[0]);
   }
 
-  auto solve(auto g) {
+  template<typename W>
+  auto solve(vector<vector<pair<int, W>>> g) {
     dp.resize(sz(g));
-    dfs0(0, 0, g);
-    dfs1(0, 0, g);
+    dfs0(g, 0);
+    dfs1(g, 0);
     return dp;
   }
 };
\ No newline at end of file