regular backup

home-manager/home.nix

@@ -174,6 +174,9 @@ in {
     pkgs.nix-index
     pkgs.rclone
     pkgs.sshfs
+    pkgs.usbutils
+    pkgs.udiskie
+    pkgs.udisks
 
     # Pwn
     pkgs.nmap
@@ -364,6 +367,7 @@ in {
       # This plugin seems to break terminfo when default shell of a terminal emulator is set to zsh.
       # set -g @plugin 'tmux-plugins/tmux-sensible'
       set -g @plugin 'erikw/tmux-powerline'
+      set -g @plugin 'tmux-plugins/tmux-yank'
       run '${config.xdg.configHome}/tmux/plugins/tpm/tpm'
     '';
   };

nvim/lua/snippets/hierholzer.lua

@@ -0,0 +1,66 @@
+return [=[
+struct hierholzer {
+    struct edge_t {
+        int from, to, rev, stale;
+        edge_t(int from, int to, int rev, int stale) : from(from), to(to), rev(rev), stale(stale) {}
+    };
+    int n;
+    vector<edge_t> edges;
+    vector<vector<int>> ch;
+    quick_union qu;
+
+    hierholzer(int n) : n(n), ch(n + 1), qu(n + 1) {}
+
+    void add_edge(int u, int v) {
+        int left = edges.size(), right = left + 1;
+        edges.emplace_back(u, v, right, false);
+        edges.emplace_back(v, u, left, false);
+        ch[u].emplace_back(left);
+        ch[v].emplace_back(right);
+        qu.merge(u, v);
+    }
+
+    optional<vector<int>> solve() {
+        if (qu.query_size(1) != n) {
+            return nullopt;
+        }
+
+        int odd = 0;
+        int last_odd;
+        for (int i = 1; i <= n; ++i) {
+            if (ch[i].size() % 2) {
+                odd += 1;
+                last_odd = i;
+            }
+        }
+
+        int start;
+        if (odd == 0) {
+            start = 1;
+        } else if (odd == 2) {
+            start = last_odd;
+        } else {
+            return nullopt;
+        }
+
+        vector<int> res;
+
+        auto dfs = [&] (auto&& dfs, int v) -> void {
+            while (ch[v].size()) {
+                int i = ch[v].back();
+                ch[v].pop_back();
+                if (not edges[i].stale) {
+                    edges[i].stale = true;
+                    edges[edges[i].rev].stale = true;
+                    dfs(dfs, edges[i].to);
+                }
+            }
+            res.emplace_back(v);
+        };
+        dfs(dfs, start);
+
+        return res;
+    }
+};
+
+]=]

nvim/lua/snippets/init.lua

@@ -76,6 +76,19 @@ ls.add_snippets(nil, {
     }
 })
 
+local quick_union_rollback = require('snippets.quick-union-rollback')
+ls.add_snippets(nil, {
+    cpp = {
+        snip({
+            trig = 'quick_union_rollback',
+            namr = 'quick_union_rollback',
+            dscr = 'Union Find (with Rollback)',
+        },{
+            text(lines(quick_union_rollback))
+        })
+    }
+})
+
 local sparse_table = require('snippets.sparse-table')
 ls.add_snippets(nil, {
     cpp = {
@@ -339,3 +352,17 @@ ls.add_snippets(nil, {
         })
     }
 })
+
+local hierholzer = require('snippets.hierholzer')
+ls.add_snippets(nil, {
+    cpp = {
+        snip({
+            trig = 'hierholzer',
+            namr = 'hierholzer',
+            dscr = 'Find Euler path',
+        },{
+            text(lines(hierholzer))
+        })
+    }
+})
+

nvim/lua/snippets/quick-union-rollback.lua

@@ -0,0 +1,46 @@
+return [=[
+class quick_union {
+public:
+    size_t n;
+    vector<size_t> c, sz;
+    vector<pair<size_t, size_t>> history;
+public:
+    quick_union(size_t n) : n(n), c(n), sz(n) {
+        iota(c.begin(), c.end(), 0);
+        sz.assign(n, 1);
+    }
+
+    size_t query(size_t i) {
+        if (c[i] != i) return query(c[i]);
+        return c[i];
+    }
+
+    void merge(size_t i, size_t j) {
+        if (connected(i, j)) {
+            history.emplace_back(n, n);
+        } else {
+            i = query(i), j = query(j);
+            if (sz[i] > sz[j]) swap(i, j);
+            history.emplace_back(i, j);
+            sz[j] += sz[i];
+            c[i] = j;
+        }
+    }
+
+    bool connected(size_t i, size_t j) {
+        return query(i) == query(j);
+    }
+
+    size_t query_size(size_t i) {
+        return sz[query(i)];
+    }
+
+    void rollback() {
+        auto [i, j] = popback(history);
+        if (i == n and j == n) return;
+        c[i] = i;
+        sz[j] -= sz[i];
+    }
+};
+
+]=]

nvim/lua/snippets/quick-union.lua

@@ -7,12 +7,12 @@ public:
         iota(c.begin(), c.end(), 0);
         sz.assign(n, 1);
     }
-    
+
     size_t query(size_t i) {
         if (c[i] != i) c[i] = query(c[i]);
         return c[i];
     }
-    
+
     void merge(size_t i, size_t j) {
         if (connected(i, j)) return;
         sz[query(j)] += sz[query(i)];