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| // Used: 3812K 4766MS
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
typedef vector<int> VI;
#define REP(i,n) for(int i=0;i<(n);++i)
const int MAX_N = 50000;
const int MAX_Q = 200000;
const int INF = 1000000000;
// data structure for range minimum query
struct SegTree {
int size;
vector<int> dat;
SegTree(int n) {
size = 1;
while (size < n) size <<= 1;
dat = vector<int>(size * 2 - 1, INF);
}
void update(int k, int a) {
k += size-1;
dat[k] = a;
while (k > 0) {
k = (k-1) / 2;
dat[k] = min(dat[k*2+1], dat[k*2+2]);
}
}
int query(int a, int b) {
return query(a, b, 0, 0, size);
}
int query(int a, int b, int k, int l, int r) {
if (a >= r || b <= l) return INF;
if (a <= l && r <= b) return dat[k];
return min(query(a, b, k*2+1, l, (l+r)/2),
query(a, b, k*2+2, (l+r)/2, r));
}
};
void solve(int N, int Q, VI& heights, VI& A, VI& B) {
SegTree sgMin(N);
REP(i, N) sgMin.update(i, heights[i]);
SegTree sgMax(N);
REP(i, N) sgMax.update(i, -heights[i]);
REP(i, Q) {
int minH = sgMin.query(A[i]-1, B[i]);
int maxH = -sgMax.query(A[i]-1, B[i]);
cout << maxH - minH << endl;
}
}
int main() {
cin.tie(0);
ios::sync_with_stdio(false);
int N, Q; cin >> N >> Q;
VI heights(N);
REP(i, N) cin >> heights[i];
VI A(Q), B(Q);
REP(i, Q) cin >> A[i] >> B[i];
solve(N, Q, heights, A, B);
}
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