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FREQUENT

FREQUENT

                                                        segment tree

#include <iostream>
#include <algorithm>
#include <stdio.h>

#define sf(i) scanf("%d", &i)
#define pf(i) printf("%d\n", i)
#define pii pair<int, int>
#define mp make_pair
#define f first // value
#define s second //frequency
#define FOR(a, b) for(int i = a; i < b; i++)

using namespace std;

const int N = 100001;

struct node
{
    pii m;
    pii l;
    pii r;
};

int n, q;
int arr[N];
node seg[4 * N];

node combine(node &a, node &b)
{
    node res;

    if(a.l.f == b.r.f) //if all the elements are same
    {
        res.l.f = res.r.f = res.m.f = a.l.f;
        res.l.s = res.r.s = res.m.s = a.l.s + b.r.s;
    }
    else
    {
        res.l = a.l;
        res.r = b.r;

        if(a.l.f == b.l.f) //if first element of left is same as first element of right
        {
            res.l.s = a.l.s + b.l.s;
        }
        if(a.r.f == b.r.f)
        {
            res.r.s = a.r.s + b.r.s;
        }

        if(a.m.s > b.m.s)
            res.m = a.m;
        else
            res.m = b.m;

       if(a.r.f == b.l.f){
            int temp = a.r.s + b.l.s;
            if(temp > res.m.s){
                res.m.f = a.r.f;
                res.m.s = temp;
            }
       }
    }

    return res;
}

void buildTree(int l, int r, int index)
{
    if(l == r)
    {
        seg[index].m = mp(arr[l], 1);
        seg[index].l = mp(arr[l], 1);
        seg[index].r = mp(arr[l], 1);
    }
    else
    {
        int mid = (l + r) / 2;
        buildTree(l, mid, index * 2);
        buildTree(mid + 1, r, (index * 2) + 1);

        seg[index] = combine(seg[2 * index], seg[2 * index + 1]);
    }
}

node query(int l, int r, int qs, int qe, int index)
{
    if(qs <= l && (qe >= r))
        return seg[index];

    int mid = (l + r) / 2;
    if(qe <= mid)
    {
        return query(l, mid, qs, qe, 2 * index);
    }
    if(qs > mid)
    {
        return query(mid + 1, r, qs, qe, 2 * index + 1);
    }

    node a = query(l, mid, qs, qe, 2 * index);
    node b = query(mid + 1, r, qs, qe, 2 * index + 1);

    return combine(a, b);
}

int main()
{
    int qs, qe;
    while(sf(n) == 1)
    {
        if(n == 0)
            break;
        sf(q);
        FOR(1, n + 1)
        {
            sf(arr[i]);
        }

        buildTree(1, n, 1);

        FOR(0, q)
        {
            sf(qs);
            sf(qe);
            node result = query(1, n, qs, qe, 1);
            pf(result.m.s);
        }
    }
    return 0;
}

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