Submission #871074

#	Time	Username	Problem	Language	Result	Execution time	Memory
871074		Pekiban	Bitaro's travel (JOI23_travel)	C++17	0 / 100	80 ms	85588 KiB

travel

#include <bits/stdc++.h>
    
using namespace std;
    
const int mxN = 2e5+2, LOG = 20;
int mx[LOG][mxN], mn[LOG][mxN], lg[mxN];
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    lg[1] = 0;
    for (int i = 2; i < mxN; ++i) {
        lg[i] = lg[i/2]+1;
    }
    int n;
    cin >> n;
    int a[n+2]; set<pair<int, int>> s;
    for (int i = 1; i <= n; ++i) {
        cin >> a[i];
        s.insert({a[i], i});    
    }
    for (int i = 1; i <= n; ++i) {
        if (i != 1) mx[0][i] = 2*a[i] - a[i-1];
        if (i != n) mn[0][i] = 2*a[i] - a[i+1];
    }
    for (int i = 1; i < LOG; ++i) {
        for (int j = 1; j <= n; ++j) {
            mx[i][j] = max(mx[i-1][j], mx[i-1][j + (1 << (i - 1))]);
            mn[i][j] = min(mn[i-1][j], mn[i-1][j + (1 << (i - 1))]);
        }
    }
    auto mnq = [&](int l, int r) {
        return min(mn[lg[r-l+1]][l], mn[lg[r-l+1]][r-(1 << lg[r-l+1]) + 1]);
    };
    auto mxq = [&](int l, int r) {
        return max(mx[lg[r-l+1]][l], mx[lg[r-l+1]][r-(1 << lg[r-l+1]) + 1]);
    };
    int q;
    cin >> q;
    while (q--) {
        int x;
        cin >> x;
        auto it = s.lower_bound({x, 0});
        int b = 0;
        if (it != s.end()) {
            b = (*it).second;
            if (it != s.begin() && abs(x-a[b-1]) <= abs(x-a[b]))    b--;
        } 
        else {
            b = n;
        }
        long long ans = abs(x-a[b]) + a[n] - a[1]; // verovatno staje u int
        int l = b, r = b; // dir = 1 => idi desno, dir = 0 => idi levo.
        bool dir = (b == 1 ? 1 : (b == n ? 0 : (a[b] - a[b-1] <= a[b+1] - a[b] ? 0 : 1)));
        while (l != 1 && r != n) {
            if (dir) {
                if (r == n-1 || mnq(r+1, n-1) > a[l-1]) {
                    ans += a[n] - a[l];
                    break;
                }
                int le = r+1, ri = n-1, t = 0;
                while (le <= ri) {
                    int mid = (le + ri)/2;
                    if (mnq(r+1, mid) <= a[l-1]) {
                        t = mid;
                        ri = mid-1;
                    }
                    else {
                        le = mid+1;
                    }
                }
                ans += a[t] - a[l];
                r = t;
            }
            else {
                if (l == 2 || mxq(2, l-1) <= a[r+1]) {
                    ans += a[r] - a[1];
                    break;
                }
                int le = 2, ri = n-1, t = 0;
                while (le <= ri) {
                    int mid = (le + ri)/2;
                    if (mxq(mid,  l-1) > a[r+1]) {
                        t = mid;
                        le = mid+1;
                    }
                    else {
                        ri = mid-1;
                    }
                }
                ans += a[r] - a[t];
                l = t;
            }
            dir ^= 1;
        }
        cout << ans << '\n';
    }
}

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