RMQSQ_SPRASE_TABLE_SOLUTION.cpp

Author: offamitkumar

Tutorial/RMQSQ_SPRASE_TABLE_SOLUTION.cpp

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+#include <cstdio>
+#include <iostream>
+#include <string>
+#include <algorithm>
+#include <utility>
+#include <queue>
+#include <stack>
+#include <string>
+#include <cstring>
+#include <cmath>
+#include <map>
+#include <vector>
+#include <array>
+#include <set>
+#include <climits>
+#include <sstream>
+#include <iomanip>
+#include <cassert>
+#include <bitset>
+#include <numeric>
+using namespace std;
+#define MOD 1000000007
+#define MAXN 100004
+#define K 17
+long long log_table[MAXN+1];
+long long sparse_table[MAXN][K];
+long long arr[MAXN];
+long long n , q , qs , qe;
+void pre(void){ // generating the log table fast 
+    log_table[1] = 0;
+    for(int i=2; i <= MAXN; ++i){
+        log_table[i] = log_table[i/2]+1;
+    }
+    return; 
+}
+int main(void){
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+    cout.tie(nullptr);
+
+#ifdef HELL_JUDGE
+    freopen("input","r",stdin);
+    freopen("output","w",stdout);
+    freopen("error","w",stderr);
+#endif 
+    pre();
+    // for range minimum query f(x,y) = min(x,y)
+    cin>>n;
+    for(int i=0;i<n;++i){
+        cin>>arr[i];
+        sparse_table[i][0] = arr[i];
+    }
+    for(int j=1;j<=K;++j){ // 2^j value starting from index i
+        for(int i=0;i+(1<<j)<=n;++i){
+            sparse_table[i][j] = min(sparse_table[i][j-1],sparse_table[i+(1<<(j-1))][j-1]);
+        }
+    }
+    cin>>q;
+    while(q--){
+        cin>>qs>>qe;
+        int j= log_table[qe-qs+1];
+        cout<<min(sparse_table[qs][j],sparse_table[qe-(1<<j)+1][j])<<endl;
+    }
+    return 0;
+}