This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include<bits/stdc++.h>
using namespace std;
 
#define INF 1234567890
#define ll long long
inline int64_t gilbertOrder(int x, int y, int pow, int rotate) {
	if (pow == 0) {
		return 0;
	}
	int hpow = 1 << (pow-1);
	int seg = (x < hpow) ? (
		(y < hpow) ? 0 : 3
	) : (
		(y < hpow) ? 1 : 2
	);
	seg = (seg + rotate) & 3;
	const int rotateDelta[4] = {3, 0, 0, 1};
	int nx = x & (x ^ hpow), ny = y & (y ^ hpow);
	int nrot = (rotate + rotateDelta[seg]) & 3;
	int64_t subSquareSize = int64_t(1) << (2*pow - 2);
	int64_t ans = seg * subSquareSize;
	int64_t add = gilbertOrder(nx, ny, pow-1, nrot);
	ans += (seg == 1 || seg == 2) ? add : (subSquareSize - add - 1);
	return ans;
}
 
struct Node {
	int l, r, i;
	int64_t ord;
 
	inline void calcOrder() {
		ord = gilbertOrder(l, r, 21, 0);
	}
};
 
inline bool operator<(const Node &a, const Node &b) {
	return a.ord < b.ord;
}
int N, Q;
int A[100101], B[100101], cnt[100101];
ll res[100101];
vector<Node> q;
priority_queue<ll> pq, del;
vector<int> com;
int main()
{
	scanf("%d %d", &N, &Q);
	for(int i=1; i<=N; i++)
	{
		scanf("%d", &A[i]);
		com.push_back(A[i]);
	}
	// 좌표 압축
	sort(com.begin(), com.end());
	com.erase(unique(com.begin(), com.end()), com.end());
	for(int i=1; i<=N; i++)
		B[i] = lower_bound(com.begin(), com.end(), A[i]) - com.begin();
	// 오프라인 쿼리
	for(int i=1; i<=Q; i++)
	{
		int l, r;
		scanf("%d %d", &l, &r);
		q.push_back({l, r, i});
	}
	sort(q.begin(), q.end());
	// MO's
	int l = 1, r = 0; // [l, r]
	for(int i=0; i<q.size(); i++)
	{
		int nl = q[i].l, nr = q[i].r, idx = q[i].i;
		while(r < nr)
		{
			r++;
			if (cnt[B[r]]) del.push((ll)A[r]*cnt[B[r]]);
			cnt[B[r]]++;
			pq.push((ll)A[r]*cnt[B[r]]);
		}
		while(l < nl)
		{
			del.push((ll)A[l]*cnt[B[l]]);
			cnt[B[l]]--;
			if (cnt[B[l]]) pq.push((ll)A[l]*cnt[B[l]]);
			l++;
		}
		while(nl < l)
		{
			l--;
			if (cnt[B[l]]) del.push((ll)A[l]*cnt[B[l]]);
			cnt[B[l]]++;
			pq.push((ll)A[l]*cnt[B[l]]);
		}
		while(nr < r)
		{
			del.push((ll)A[r]*cnt[B[r]]);
			cnt[B[r]]--;
			if (cnt[B[r]]) pq.push((ll)A[r]*cnt[B[r]]);
			r--;
		}
		while(!pq.empty() && !del.empty() && pq.top() == del.top())
			pq.pop(), del.pop();
		// 구간이 비는 경우는 없다.
		res[idx] = pq.top();
	}
	for(int i=1; i<=Q; i++)
		printf("%lld\n", res[i]);
	return 0;
}
Compilation message (stderr)
historic.cpp: In function 'int main()':
historic.cpp:73:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Node>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   73 |  for(int i=0; i<q.size(); i++)
      |               ~^~~~~~~~~
historic.cpp:50:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   50 |  scanf("%d %d", &N, &Q);
      |  ~~~~~^~~~~~~~~~~~~~~~~
historic.cpp:53:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   53 |   scanf("%d", &A[i]);
      |   ~~~~~^~~~~~~~~~~~~
historic.cpp:66:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   66 |   scanf("%d %d", &l, &r);
      |   ~~~~~^~~~~~~~~~~~~~~~~| # | Verdict  | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict  | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict  | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict  | Execution time | Memory | Grader output | 
|---|
| Fetching results... |