Submission #949461

#	Time	Username	Problem	Language	Result	Execution time	Memory
949461		hngwlog	Real Mountains (CCO23_day1problem2)	C++14	0 / 25	0 ms	344 KiB

Main

#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define _size(x) (int)x.size()

int n;
long long ans = 0;
vector<long long> h, newH;

void solve() {
    
    set<pair<long long, long long>> st;
    for (int i = 0; i < n; i++) {
        if (h[i] == newH[i]) {
            if (!i) st.insert({newH[i], newH[i]});
            else if (newH[i] != newH[i - 1]) st.insert({newH[i], newH[i]});
            continue;
        }
        vector<pair<long long, long long>> g;
        auto it = st.upper_bound({h[i], h[i]});
        if (it != st.begin()) {
            it--;
            if (it->se < h[i]) it++;
        }
        long long x = h[i];
        while (true) {
            g.push_back({it->fi, it->se});
            if (it->fi > x) {
                if (it->fi > newH[i]) {
                    ans += it->fi * (newH[i] - x);
                    g.pop_back();
                    break;
                }
                ans += it->fi * (it->fi - x);
                x = it->fi;
            }
            long long maxx = min(it->se, newH[i]);
            ans += (maxx + x + 1) * (maxx - x) / 2;
            x = maxx;
            if (x == newH[i]) break;
            it++;
        }
        for (auto seg: g) st.erase({seg.fi, seg.se});
        if (_size(g)) st.insert({min(g[0].fi, h[i]), max(g.back().se, newH[i])});
        else st.insert({h[i], newH[i]});    
    }
}

int32_t main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
    
    cin >> n;
    h.resize(n);
    long long maxValue = 0;
    for (int i = 0; i < n; i++) {
        cin >> h[i];
        maxValue = max(maxValue, h[i]);
    }
    newH.resize(n);
    for (int i = 0; i < n; i++) {
        if (h[i] == maxValue) break;
        newH[i] = max(i ? newH[i - 1] : 0, h[i]);
    }
    for (int i = n - 1; i >= 0; i--) {
        if (h[i] == maxValue) break;
        newH[i] = max(i < n - 1 ? newH[i + 1] : 0, h[i]);
    }
    for (int i = 0; i < n; i++) if (newH[i] == 0) newH[i] = maxValue;
    // for (int i = 0; i < n; i++) cout << "#" << i << ": " << h[i] << " and " << newH[i] << '\n'; 
    solve();
    reverse(h.begin(), h.end());
    reverse(newH.begin(), newH.end());
    solve();
    for (int i = 0; i < n; i++) ans += (newH[i] - 1 + h[i]) * (newH[i] - h[i]) / 2;
    cout << ans << '\n';
    return 0;
}

• Subtask 1: 0 / 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