Maximum Absurdity

#include <iostream>
#include <cstdio>
#include <vector>
using namespace std;

inline __int64 get_sum(const vector<__int64> &sum, int l, int r)
{
    return (l == 0) ? sum[r] : (sum[r] - sum[l - 1]);
}

int main()
{
    int n, k;
    scanf("%d %d", &n, &k);
    vector<__int64> a(n), sum(n);
    scanf("%I64d", &a[0]);
    sum[0] = a[0];
    for (int i = 1; i < n; ++i)
    {
        scanf("%I64d", &a[i]);
        sum[i] = sum[i - 1] + a[i];
    }
    pair<int, int> ans = make_pair(n - 2 * k, n - k);
    __int64 ans_sum = get_sum(sum, n - 2 * k, n - k - 1) + get_sum(sum, n - k, n - 1);
    pair<int, __int64> suff_max = make_pair(n - k, get_sum(sum, n - k, n - 1));
    for (int i = n - 2 * k - 1; i >= 0; --i)
    {
        __int64 cur = get_sum(sum, i + k, i + 2  * k - 1);
        if (cur >= suff_max.second)
            suff_max = make_pair(i + k, cur);
        cur = get_sum(sum, i, i + k - 1) + suff_max.second;
        if (cur >= ans_sum)
        {
            ans_sum = cur;
            ans = make_pair(i, suff_max.first);
        }
    }
    printf("%d %d\n", ans.first + 1, ans.second + 1);
    return 0;
}