最近学了树状数组，所以写了一发树状数组求RMQ

#include <bits/stdc++.h>
using namespace std;
#define lc p << 1
#define rc (p << 1) | 1
#define lowbit(x) (x&(-x))
#define endl '\n'
#define endln " \n"[i == n]
#define endlm " \n"[j == m]
// #define int long long
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int mod = 998244353;
const int MOD = 1e9 + 7;
const int N = 2e6 + 5;
const int INF = 0x3f3f3f3f;
const int inf = 0xc0c0c0c0;
int a[N], b[N],sum[N],tr[N],tr1[N],tr2[N];
pii arr[N];
int t, n, m, k, q;

void updata(int pos,int x)
{
    for(int i=pos;i<=n;i+=lowbit(i)){
        tr[i]=min(x,tr[i]);
    }
}
int query(int l,int r)
{
    if(l==r) return a[l];
    if(r-lowbit(r)>l) return min(tr[r],query(l,r-lowbit(r)));
    return min(query(l,r-1),a[r]);
}

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    memset(tr,INF,sizeof(tr));
    cin>>n>>q;
    for(int i=1;i<=n;i++){
        cin>>a[i];
        updata(i,a[i]);
    }
    int l,r;
    while(q--){
        cin>>l>>r;
        cout<<query(l,r)<<' ';
    }
    return 0;
}