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RMQ_Sparse_Matrix.cpp
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RMQ_Sparse_Matrix.cpp
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#include<bits/stdc++.h>
using namespace std;
int main(){
int arr[]= {11,2,101,13,21,20,41,5,4,12,34,2,3,45,67,54,12,34,23,34,53,45,12,32};
int n= 24;
//count the bits in which n can be represented
int m = ceil(log2(n));
vector<vector<int>> dp(2*n, vector<int>(m,INT_MAX));
//traversing over all bits
for(int j=0;j<m;j++){
for(int i=0;i<n;i++){
if(j==0){
dp[i][j]=arr[i];
}else{
dp[i][j]=min(dp[i][j-1], dp[i+(1<<(j-1))][j-1]);
}
}
}
for(int i=0;i<n;i++){
for(int j=0;j<m;j++){
cout<<dp[i][j]<<" ";
}
cout<<"\n";
}
//query
int q;
cin>>q;
while(q--){
int l,r;
cin>>l>>r;
int x = r-l+1, ans = INT_MAX, cur=1;
for(int i=m-1;i>=0;i--){
//set bit
if((x&(1<<i))!= 0){
ans = min(ans,dp[cur][i]);
cur+=(1<<i);
}
}
cout<<"Minimum of range"<<l<<" to "<<r<<" is: "<<ans<<"\n";
}
return 0;
}