Submission #1029260

#	Time	Username	Problem	Language	Result	Execution time	Memory
1029260		adaawf	Bitaro's travel (JOI23_travel)	C++17	15 / 100	139 ms	65108 KiB

travel

#include <iostream>
#include <algorithm>
using namespace std;
long long int a[200005], l[200005][19], ll[200005], la[200005][19];
long long int check(int x, int y) {
    int h = ll[y - x + 1];
    return max(l[x][h], l[y - (1 << h) + 1][h]);
}
long long int check2(int x, int y) {
    int h = ll[y - x + 1];
    return min(la[x][h], la[y - (1 << h) + 1][h]);
}
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int n;
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
    }
    for (int i = 2; i <= n; i++) {
        l[i][0] = a[i] * 2 - a[i - 1];
        ll[i] = ll[i / 2] + 1;
    }
    for (int i = 1; i < n; i++) {
        la[i][0] = a[i] * 2 - a[i + 1];
    }
    l[1][0] = 1e18;
    la[n][0] = -1e18;
    for (int i = 1; i <= 18; i++) {
        for (int j = 2; j <= n - (1 << i) + 1; j++) {
            l[j][i] = max(l[j][i - 1], l[j + (1 << (i - 1))][i - 1]);
        }
        for (int j = 1; j < n - (1 << i) + 1; j++) {
            la[j][i] = min(la[j][i - 1], la[j + (1 << (i - 1))][i - 1]);
        }
    }
    int q;
    cin >> q;
    for (int jj = 0; jj < q; jj++) {
        long long int x, c = 0, l, r, flag = 0;
        cin >> x;
        if (x >= a[n]) {
            c = x - a[n];
            l = r = n;
        }
        else if (x <= a[1]) {
            c = a[1] - x;
            l = r = 1;
        }
        else {
            int h = lower_bound(a + 1, a + n + 1, x) - a;
            if (a[h] - x >= x - a[h - 1]) {
                l = r = h - 1;
                c += x - a[h - 1];
            }
            else {
                l = r = h;
                c = a[h] - x;
            }
        }
        while (l != 1 && r != n) {
            if (flag == 0) {
                int ll = 1, rr = l, res = 1;
                while (ll <= rr) {
                    int mid = (ll + rr) / 2;
                    if (check(mid, l) > a[r + 1]) {
                        res = mid;
                        ll = mid + 1;
                    }
                    else rr = mid - 1;
                }
                c += a[l] - a[res];
                l = res;
                c += a[r + 1] - a[l];
                r++;
            }
            else {
                int ll = r, rr = n, res = n;
                while (ll <= rr) {
                    int mid = (ll + rr) / 2;
                    if (check2(r, mid) <= a[l - 1]) {
                        res = mid;
                        rr = mid - 1;
                    }
                    else ll = mid + 1;
                }
                c += a[res] - a[r];
                r = res;
                c += a[r] - a[l - 1];
                l--;
            }
            //cout << l << " " << r << " " << c << '\n';
            flag ^= 1;
        }
        if (flag == 1 && r == n) c += (l != 1) * (a[n] - a[1]);
        else if (flag == 1 && l == 1) c += a[n] - a[r];
        else if (flag == 0 && r == n) c += a[l] - a[1];
        else c += a[n] - a[1];
        cout << c << '\n';
    }
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 0 / 30
• Subtask 4: 0 / 55