diff --git a/graph/lca.cpp b/graph/lca.cpp
index cffce0a2e4c55b6ba1e3ae4af400eea91fbb87b6..79f835dc898f4a580b9f547ae59b0679babbdbf1 100644
--- a/graph/lca.cpp
+++ b/graph/lca.cpp
@@ -24,7 +24,7 @@ void dfs(int v, int p = -1, int c = 0) {
   if (p + 1)
     h[v] = h[p] + 1;
 
-  for (int i = 1; i < MAXLOG; i++)
+  for (int i = 1; i < MAXLOG; ++i)
     if (par[v][i - 1] + 1) {
       par[v][i] = par[par[v][i - 1]][i - 1];
       //* cost[v][i] += cost[v][i - 1] + cost[par[v][i - 1]][i - 1];
@@ -36,7 +36,7 @@ void dfs(int v, int p = -1, int c = 0) {
       dfs(u.fi, v, u.se);
 }
 
-// Preprocess tree with rooted at v
+// Preprocess tree rooted at v
 void preprocess(int v) {
   memset(par, -1, sizeof par);
   memset(cost, 0, sizeof cost);
@@ -50,7 +50,7 @@ int query(int p, int q) {
   if (h[p] < h[q])
     swap(p, q);
 
-  for (int i = MAXLOG - 1; i >= 0; i--)
+  for (int i = MAXLOG - 1; i >= 0; --i)
     if (par[p][i] + 1 && h[par[p][i]] >= h[q]) {
       //* ans += cost[p][i];
       //** ans = max(ans, cost[p][i]);
@@ -61,7 +61,7 @@ int query(int p, int q) {
     return p;
     //*** return ans;
 
-  for (int i = MAXLOG - 1; i >= 0; i--)
+  for (int i = MAXLOG - 1; i >= 0; --i)
     if (par[p][i] + 1 && par[p][i] != par[q][i]) {
       //* ans += cost[p][i] + cost[q][i];
       //** ans = max(ans, max(cost[p][i], cost[q][i]));