Submission #968476

#	Time	Username	Problem	Language	Result	Execution time	Memory
968476		weakweakweak	Real Mountains (CCO23_day1problem2)	C++17	3 / 25	14 ms	27472 KiB

Main

//我好笨，聽解了
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
 
const int M = 1e6 + 3, N = M + 20, INF = N * 10;
 
int o[N], n;
vector <int> v[N];
 
struct segmenttree {
    int a[N << 2];
    void build (int l, int r, int id) {
        if (l == r) {
            a[id] = o[l];
            return;
        }
        int mid = (l + r) >> 1;
        build (l, mid, id << 1); build (mid + 1, r, id << 1 | 1);
        a[id] = min(a[id << 1], a[id << 1 | 1]);
    }
    int query (int l, int r, int ql, int qr, int id) {
        if (ql < 1 or qr > n or ql > qr) return INF;
        if (ql <= l and r <= qr) return a[id];
        int mid = (l + r) >> 1, ans = INT_MAX;
        if (ql <= mid) ans = min(ans, query(l, mid, ql, qr, id << 1));
        if (qr > mid)  ans = min(ans, query(mid + 1, r, ql, qr, id << 1 | 1));
        return ans;
    }
    void update (int l, int r, int pos, int val, int id) {
        if (l == r) {
            a[id] = o[pos] = val;
            return;
        }
        int mid = (l + r) >> 1;
        if (pos <= mid) update(l, mid, pos, val, id << 1);
        else update(mid + 1, r, pos, val, id << 1 | 1);
        a[id] = min(a[id << 1], a[id << 1 | 1]);
    }
}seg;
 
 
int main () {
    ios_base::sync_with_stdio(false); cin.tie(0);
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> o[i];
        v[o[i]].push_back(i);
    }
 
    seg.build(1, n, 1);
 
    set<int> st;
    ll ans = 0;
    for (int h = 1; h <= 1000000; h++) {
        for (int x : v[h]) {
            st.insert(x);
            seg.update(1, n, x, INF, 1);
        }
        while (st.size()) {
            int i = *st.begin();
            int left = seg.query(1, n, 1, i - 1, 1),   right = seg.query(1, n, i + 1, n, 1);
            if (left == INF or right == INF) st.erase(i);
            else break;
        }
        while (st.size()) {
            int i = *st.rbegin();
            int left = seg.query(1, n, 1, i - 1, 1),   right = seg.query(1, n, i + 1, n, 1);
            if (left == INF or right == INF) st.erase(i);
            else break;
        }
        if (st.size() == 1) {
            int i = *st.begin();
            int left = seg.query(1, n, 1, i - 1, 1),   right = seg.query(1, n, i + 1, n, 1);
            ans += (left + h + right) % M;
        }
        else if (st.size() >= 2) {
            int il = *st.begin(), ir = *st.rbegin();
            ll left = seg.query(1, n, 1, il - 1, 1),   right = seg.query(1, n, ir + 1, n, 1);
            ll mid = seg.query(1, n, il + 1, ir - 1, 1);
            ans += min( left + right + h  +  min(left, right) + (h + 1) + h ,
                        (mid + h) * 2 + (left + right) ) % M;
            ans += (st.size() - 2)  *  (h + h + 1LL + h + 1)  %  M;
        }
        ans %= M;
    }
 
    cout << ans << '\n';
return 0;}

• Subtask 1: 3 / 3
• Subtask 2: 0 / 3
• Subtask 3: 0 / 3
• Subtask 4: 0 / 3
• Subtask 5: 0 / 4
• Subtask 6: 0 / 5
• Subtask 7: 0 / 4