Min Sparse Table

Range Queries/minSparseTable.cpp

@@ -0,0 +1,49 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+
+//Sparse Table for minimum value query.
+
+vector<vector<int>> table;
+
+void precomputeSparseTable(int n, vector<int>& arr){
+
+	int lPower = log2(n);
+
+	table.resize(n+1,vector<int>(lPower+1));
+
+	for(int p = 0 ; p <= lPower ; p++ ){
+		for(int i = 0 ; i + pow(2,p) - 1 <= n ; i++ ){
+			if( p == 0 ){
+				table[i][p] = arr[i];
+				continue;
+			}
+
+			table[i][p] = min(table[i][p-1],table[i+pow(2,p-1)][p-1]);
+		}
+	}
+
+	// for(int i = 0 ; i <= n ; i++ ){
+	// 	cout << i << " : ";
+	// 	for(int p = 0 ; p <= lPower ; p++ ){
+	// 		cout << table[i][p] << " ";
+	// 	}
+	// 	cout << endl;
+	// }
+}
+
+int main(int argc,char* argv[]){
+
+	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
+
+	int n,q;
+	cin>>n>>q;
+
+	vector<int> arr(n);
+	for(int i = 0 ; i < n ; i++ ){
+		cin>>arr[i];
+	}
+
+	precomputeSparseTable(n,arr);
+}