不能理解为啥会RE，感觉很对没问题啊

/*
   卫风·芄兰
芄兰之支,童子佩觿.
虽则佩觿,能不我知?
容兮遂兮,垂带悸兮.
芄兰之叶,童子佩韘.
虽则佩韘,能不我甲?
容兮遂兮,垂带悸兮.
*/
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define PII pair<int,int>
#define tul tuple<int,int,int>
#define rep(i,a,b) for(int i=a;i<=b;++i)
#define rep_(i,a,b) for(int i=a;i>=b;--i)
#define all(x) x.begin(),x.end()
#define bp(x) __builtin_popcountll(x)
#define cy cout<<"YES"<<endl
#define cn cout<<"NO"<<endl
#define lc (rt<<1)
#define rc (rt<<1|1)
mt19937_64 rnd(time(0));
const int N=3e5+5,yyx=1e9+7;
vector<int> to[N],dp[N];
int n,q,a[N];
inline int mod(int x){
  return (x%yyx+yyx)%yyx;
}
inline int cmin(int &x,int y){
  return x>y?x=y,1:0;
}
inline int cmax(int &x,int y){
  return x<y?x=y,1:0;
}
inline void solve(){
  cin>>n>>q;
  rep(i,1,n) cin>>a[i];
  vector<int> st;
  rep_(i,n,1){
    if(st.size()) dp[i]=st;
    while(st.size()&&a[st.back()]<a[i]) st.pop_back();
    st.push_back(i);
  }
  rep(i,1,q){
    int l,r;cin>>l>>r;
    if(r==n||!dp[l].size()){
        cout<<0<<endl;continue;
    }
    //for(auto c:dp[l]) cout<<c<<" ";
    //cout<<endl;
    int x=lower_bound(all(dp[l]),r,greater<int>())-dp[l].begin();
    cout<<x<<endl;
  }
}
signed main(){
  cin.tie(0)->sync_with_stdio(0);
  //freopen("D://321//in.txt","r",stdin);
  //freopen("D://321//out.txt","w",stdout);
  int _=1;
  //cin>>_;
  while(_--)
  solve();
  return 0;
}