Create sparse_table.cpp

Data Structures/sparse_table.cpp

@@ -0,0 +1,42 @@
+// Sparse Table
+// Range Min Queries
+// Time - O(1)
+// Space - O(N*32)
+
+template <typename T>
+class SparseTable {
+public:
+    using F = function<T(const T&, const T&)>;
+
+    int n;
+    vector<vector<T>> mat;
+    F f;
+    SparseTable(): n(), mat(), f() {}
+
+    template <typename U>
+    SparseTable(const U& arr, int n, F f): n(n), f(f), mat((int)log2(n) + 1) {
+        mat[0].resize(n);
+        for (int i = 0; i < n; i++)
+            mat[0][i] = T(arr[i]);
+        for (int j = 1; j < mat.size(); j++) {
+            mat[j].resize(n - (1 << j) + 1);
+            for (int i = 0; i + (1 << j) <= n; i++) {
+                mat[j][i] = f(mat[j - 1][i], mat[j - 1][i + (1 << (j - 1))]);
+            }
+        }
+    }
+    T query(int l, int r) {
+        int j = 32 - __builtin_clz(r - l + 1) - 1;
+        return f(mat[j][l], mat[j][r + 1 - (1 << j)]);
+    }
+};
+
+void solve() {
+	int n; cin >> n;
+
+	vector<int> a(n);
+	for(auto &x : a) cin >> x;
+
+	SparseTable<int> gcd(a, n, [&](int a, int b) { return __gcd(a,b); });
+	SparseTable<int> mn(a, n, [&](int a, int b) { return min(a,b); });
+}