max Xor of 2 number in array

algorithms/CPlusPlus/Trie/Max-Xor-of-Two-Number-Trie.cpp

@@ -0,0 +1,145 @@
+#include <bits/stdc++.h>
+using namespace std;
+#define ll long long int
+#define for0(i, n) for (int i = 0; i < n; i++)
+#define vi vector<int>
+#define pb push_back
+#define sz(x) sizeof(x)
+#define vec(n, x) vector<int> v(n, x)
+const ll INF = 1e18;
+const ll MOD = 1000000007;
+#define hi        \
+    ll tests;     \
+    cin >> tests; \
+    while (tests--)
+#define all(x) x.begin(), x.end()
+#define readv(vec)      \
+    for (auto &x : vec) \
+    {                   \
+        cin >> x;       \
+    }
+#define PHI M_PI
+#define graph                   \
+    int V;                      \
+    cin >> V;                   \
+    vector<int> adj[V];         \
+    int e;                      \
+    for (int i = 0; i < e; i++) \
+    {                           \
+        int u, v;               \
+        cin >> u >> v;          \
+        adj[u].push_back(v);    \
+        adj[v].push_back(u);    \
+    }
+#define printv(vec)       \
+    for (auto x : vec)    \
+    {                     \
+        cout << x << ' '; \
+    }                     \
+    cout << endl;
+#define sortasc(vec) sort(all(vec));
+#define sortdes(vec) sort(vec.rbegin(), vec.rend());
+#define setpre(x) cout << fixed << setprecision(10) << x << endl
+#define kick cout << 'C' << 'a' << 's' << 'e' << ' ' << '#' << k << ':' << ' '
+struct node
+{
+    node *left;
+    node *right;
+};
+class Trie
+{
+public:
+    node *root;
+    Trie()
+    {
+        root = new node();
+    }
+
+    void insert(int x)
+    {
+        node *temp = root;
+        int idx = 31;
+        while (idx >= 0)
+        {
+            int mask = (1 << idx);
+            if (x & mask)
+            {
+                // cout<<idx<<" ";
+                if (temp->right == NULL)
+                {
+                    temp->right = new node();
+                }
+                temp = temp->right;
+            }
+            else
+            {
+                if (temp->left == NULL)
+                {
+                    temp->left = new node();
+                }
+                temp = temp->left;
+            }
+            idx--;
+        }
+    }
+    int query(int x)
+    {
+        node *temp = root;
+        int idx = 31;
+        int sol = 0;
+        while (idx >= 0)
+        {
+            int mask = (1 << idx);
+            if ((mask & x))
+            {
+                // cout<<"jo";
+                if (temp->right == NULL)
+                {
+                    temp = temp->left;
+                }
+                else
+                {
+                    sol |= mask;
+                    temp = temp->right;
+                }
+            }
+            else
+            {
+                if (temp->left == NULL)
+                {
+                    sol |= mask;
+                    temp = temp->right;
+                }
+                else
+                {
+                    temp = temp->left;
+                }
+            }
+            idx--;
+        }
+        return sol;
+    }
+};
+int main()
+{
+    int n;
+    cin >> n;
+    vector<int> nums(n);
+    Trie *t = new Trie();
+    for (auto &i : nums)
+    {
+        cin>>i;
+        t->insert(i);
+    }
+    int mx = 0;
+    // cout<<res;
+    for (auto i : nums)
+    {
+        int mask = INT_MAX;
+        int req = mask ^ i;
+        int res = t->query(req);
+        // cout<<res<<" ";
+        mx = max(mx, res ^ i);
+    }
+    cout << mx;
+}