various golf's

Author: lrvideckis

library/loops/chooses.hpp

@@ -5,4 +5,4 @@
 //! @time O(n choose k)
 //! @space O(1)
 for (int mask = (1 << k) - 1; mask < (1 << n);
-  mask = next_subset(mask))
+  mask = next_subset(mask))

library/loops/submasks.hpp

@@ -5,4 +5,4 @@
 //!   of every mask of size n
 //! @space O(1)
 for (int submask = mask; submask;
-  submask = (submask - 1) & mask)
+  submask = (submask - 1) & mask)

library/loops/supermasks.hpp

@@ -6,4 +6,4 @@
 //!   of every mask of size n
 //! @space O(1)
 for (int supermask = mask; supermask < (1 << n);
-  supermask = (supermask + 1) | mask)
+  supermask = (supermask + 1) | mask)

library/math/matrix_related/solve_linear_mod.hpp

@@ -18,9 +18,8 @@ struct solve_linear_mod {
     rep(i, 0, n) mat[i].push_back(rhs[i]);
     tie(rank, det) = row_reduce(mat, m);
     if (any_of(rank + all(mat),
-          [](vi& v) { return v.back(); })) {
+          [](vi& v) { return v.back(); }))
       return;
-    }
     sol.resize(m);
     int j = 0;
     for_each(begin(mat), begin(mat) + rank, [&](vi& v) {

library/trees/centroid_decomp.hpp

@@ -22,11 +22,7 @@ void centroid(auto& g, auto f) {
       w = u, u = *big_ch;
     }
     f(u, p);
-    for (int v : g[u]) {
-      iter_swap(ranges::find(g[v], u), rbegin(g[v]));
-      g[v].pop_back();
-      dfs(dfs, v, u);
-    }
+    for (int v : g[u]) erase(g[v], u), dfs(dfs, v, u);
   };
   dfs(dfs, 0, -1);
 }

library/trees/edge_cd.hpp

@@ -24,17 +24,16 @@ template<class G> void edge_cd(vector<G>& g, auto f) {
         if (c != -1) return c;
         siz[u] += siz[v];
       }
-    return 2 * siz[u] > m
-           ? p >= 0 && (siz[p] = m + 1 - siz[u]),
-           u : -1;
+    return 2 * siz[u] > m ? siz[p] = m + 1 - siz[u],
+                            u : -1;
   };
   auto dfs = [&](auto&& dfs, int u, int m) -> void {
     if (m < 2) return;
-    u = cent(cent, u, -1, m);
+    u = cent(cent, u, u, m);
     int sum = 0;
     auto it = partition(all(g[u]), [&](int v) {
       ll x = sum + siz[v];
-      return x * x < m * (m - x) ? sum += siz[v], 1 : 0;
+      return x * x < m * (m - x) ? sum = x : 0;
     });
     f(u, it - begin(g[u]));
     G oth(it, end(g[u]));

library/trees/hld.hpp

@@ -16,9 +16,7 @@ template<bool VALS_EDGES> struct HLD {
   HLD(auto& g): n(sz(g)), p(n), siz(n, 1), rt(n), tin(n) {
     auto dfs1 = [&](auto&& dfs1, int u) -> void {
       for (int& v : g[u]) {
-        iter_swap(ranges::find(g[v], u), rbegin(g[v]));
-        g[v].pop_back();
-        p[v] = u;
+        erase(g[v], p[v] = u);
         dfs1(dfs1, v);
         siz[u] += siz[v];
         if (siz[v] > siz[g[u][0]]) swap(v, g[u][0]);

library/trees/shallowest_decomp_tree.hpp

@@ -24,8 +24,6 @@ void shallowest(auto& g, auto f) {
   for (const vi& vec : order | views::reverse)
     for (int u : vec) {
       f(u);
-      for (int v : g[u])
-        iter_swap(ranges::find(g[v], u), rbegin(g[v])),
-          g[v].pop_back();
+      for (int v : g[u]) erase(g[v], u);
     }
 }

tests/library_checker_aizu_tests/trees/edge_cd_reroot_dp.test.cpp

@@ -81,15 +81,12 @@ int main() {
       dfs(dfs, adj[cent][i], cent, {b[e_id], c[e_id]},
         {b[e_id], c[e_id]}, i < split);
     }
-    for (int side = 0; side < 2; side++) {
-      for (
-        auto [u, curr_b, curr_c] : all_backwards[side]) {
+    for (int side = 0; side < 2; side++)
+      for (auto [u, curr_b, curr_c] : all_backwards[side])
         res[u] =
           (res[u] + 1LL * curr_b * sum_forward[!side] +
             1LL * curr_c * cnt_nodes[!side]) %
           mod;
-      }
-    }
   });
   swap(base_adj, adj);
   {

tests/library_checker_aizu_tests/trees/shallowest_lib_checker_tree_path_composite.test.cpp

@@ -59,10 +59,9 @@ int main() {
       for (int i = 0; i < ssize(adj[v]); i++) {
         int u = adj[v][i];
         line curr_line = weight[v][i];
-        if (u != p) {
+        if (u != p)
           self(self, u, v, compose(downwards, curr_line),
             compose(curr_line, upwards), forwards);
-        }
       }
     };
     for (int i = 0; i < ssize(adj[cent]); i++) {