1 files changed, 28 insertions, 25 deletions

diff --git a/graph/reroot.cpp b/graph/reroot.cpp
index eeca43e..4c6a748 100644
--- a/graph/reroot.cpp
+++ b/graph/reroot.cpp
@@ -1,39 +1,39 @@
 // Usual Tree DP can be broken down in 4 steps:
 // - Initialize dp[v] = identity
 // - Iterate over all children w and take a value for w 
-//   by looking at dp[w] and possibly the edge label of v -> w
+//	 by looking at dp[w] and possibly the edge label of v -> w
 // - combine the values of those children
-//   usually, this operation should be commutative and associative
-// - finalize the value of dp[v] after iterating over all children
-struct Reroot{
+//	 usually this operation should be commutative and associative
+// - finalize the dp[v] after iterating over all children
+struct Reroot {
 	using T = ll;
 
 	// identity element
-	T E(){}
+	T E() {}
 	// x: dp value of child
 	// e: index of edge going to child
-	T takeChild(T x, int e){}
-	T combine(T x, T y){}
+	T takeChild(T x, int e) {}
+	T comb(T x, T y) {}
 	// called after combining all dp values of children
-	T finalize(T x, int v){}
+	T fin(T x, int v) {}
 
 	vector<vector<pair<int, int>>> g;
 	vector<int> ord, pae;
 	vector<T> dp;
 
-	T dfs(int v){
+	T dfs(int v) {
 		ord.push_back(v);
-		for(auto [w, e] : g[v]){
+		for (auto [w, e] : g[v]) {
 			g[w].erase(find(all(g[w]), pair(v, e^1)));
 			pae[w] = e^1;
-			dp[v] = combine(dp[v], takeChild(dfs(w), e));
+			dp[v] = comb(dp[v], takeChild(dfs(w), e));
 		}
-		return dp[v] = finalize(dp[v], v);
+		return dp[v] = fin(dp[v], v);
 	}
 
-	vector<T> solve(int n, vector<pair<int, int>> edges){
+	vector<T> solve(int n, vector<pair<int, int>> edges) {
 		g.resize(n);
-		for(int i = 0; i < n-1; i++){
+		for (int i = 0; i < n-1; i++) {
 			g[edges[i].first].emplace_back(edges[i].second, 2*i);
 			g[edges[i].second].emplace_back(edges[i].first, 2*i+1);
 		}
@@ -41,19 +41,22 @@ struct Reroot{
 		dp.assign(n, E());
 		dfs(0);
 		vector<T> updp(n, E()), res(n, E());
-		for(int v : ord){
+		for (int v : ord) {
 			vector<T> pref(sz(g[v])+1), suff(sz(g[v])+1);
-			if(v != 0) pref[0] = takeChild(updp[v], pae[v]);
-			for(int i = 0; i < sz(g[v]); i++){
-				pref[i+1] = suff[i] = takeChild(dp[g[v][i].first], g[v][i].second);
-				pref[i+1] = combine(pref[i], pref[i+1]);
+			if (v != 0) pref[0] = takeChild(updp[v], pae[v]);
+			for (int i = 0; i < sz(g[v]); i++){
+				auto [u, w] = g[v][i];
+				pref[i+1] = suff[i] = takeChild(dp[u], w);
+				pref[i+1] = comb(pref[i], pref[i+1]);
 			}
-			for(int i = sz(g[v])-1; i >= 0; i--)
-				suff[i] = combine(suff[i], suff[i+1]);
-			for(int i = 0; i < sz(g[v]); i++)
-				updp[g[v][i].first] = finalize(combine(pref[i], suff[i+1]), v);
-			res[v] = finalize(pref.back(), v);
+			for (int i = sz(g[v])-1; i >= 0; i--) {
+				suff[i] = comb(suff[i], suff[i+1]);
+			}
+			for (int i = 0; i < sz(g[v]); i++) {
+				updp[g[v][i].first] = fin(comb(pref[i], suff[i+1]), v);
+			}
+			res[v] = fin(pref.back(), v);
 		}
 		return res;
 	}
-};
\ No newline at end of file
+};