1082 Array Queries

#include<bits/stdc++.h>
using namespace std;
#define FAST_IO ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define mx 100005
int tree[mx*3];
int arr[mx];
void build_segment(int node,int left,int right){
    if(left==right){
        tree[node]=arr[left];
        //cout<<"Index "<<node<<": "<<tree[node]<<endl;
        return;
    }
    int mid=(left+right)/2;
    build_segment(node*2, left, mid); //left subtree
    build_segment(node*2 + 1, mid+1, right); //right subtree
    tree[node]=min(tree[node*2], tree[node*2 + 1]);
    //cout<<"IndexMin "<<node<<": "<<tree[node]<<endl;
}
int query_seqment(int node,int left,int right,int ia,int ib){

    if(left>=ia && right<=ib)
        return tree[node];
    if(ia>right || ib<left)
        return INT_MAX;
    int mid=(left+right)/2;
    int p=query_seqment(node*2, left, mid, ia, ib); //left child query
    int q=query_seqment(node*2 + 1, mid+1, right, ia, ib); //right child query
    return min(p,q);


}
int main(){
    FAST_IO
    //freopen("input.txt","r",stdin);
    //freopen("output.txt","w",stdout);
    int t;
    cin>>t;
    for(int tc=1;tc<=t;tc++){
        int n,q;
        cin>>n>>q;
        for(int i=1;i<=n;i++){
            cin>>arr[i];
        }
        //root node, left most node, right most node
        build_segment(1,1,n);
        int ia,ib;
        cout<<"Case "<<tc<<":"<<endl;
        for(int i=1;i<=q;i++){
            cin>>ia>>ib;
            //root, left most, right most, from node, to node
            cout<<query_seqment(1,1,n,ia,ib)<<endl;
        }
    }
    return 0;
}