Submission #968558

#	Time	Username	Problem	Language	Result	Execution time	Memory
968558		weakweakweak	Real Mountains (CCO23_day1problem2)	C++17	25 / 25	2740 ms	129472 KiB

Main

//我好笨，聽解了
/*
x + 
*/
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
 
const int M = 1e6 + 3, N = M + 20, INF = (INT_MAX >> 1) - 3;
 
int o[N], n;
vector <int> v[N], b;
 
struct segmenttree {
    int a[N << 2];
    void build (int l, int r, int id) {
        if (l == r) {
            a[id] = b[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;
 

inline int f (int l, int r) {
    return (r - l + 1LL) * (r + l) / 2 % M;
}


int main () {
    ios_base::sync_with_stdio(false); cin.tie(0);
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> o[i];
        b.push_back(o[i]);
    }
    sort(b.begin(), b.end());
    b.erase(unique(b.begin(), b.end()), b.end());
    for (int i = 1; i <= n; i++) {
        o[i] = lower_bound(b.begin(), b.end(), o[i]) - b.begin();
        v[o[i]].push_back(i);
    }

    seg.build(1, n, 1);
 
    set<int> st;
    ll ans = 0;
    for (int h = 0; h + 1 < b.size(); h++) {
        int oh = b[h], nh = b[h + 1];
        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 += f(oh, nh - 1) + (left +right) * 1LL * (nh - oh) % 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);
            ll z = min( (left + right + min(left, right)) * 1LL * (nh - oh)      +      f(oh + 1, nh) + f(oh, nh - 1) * 2 ,
                        (left + mid + right) * 1LL * (nh - oh)     +    f(oh + 1, nh) + f(oh, nh - 1) * 2 );
            ans += z % M;
            ans += (st.size() - 2)  *  (f(oh + 1, nh) * 2LL + f(oh, nh - 1))  %  M;
        }
        ans %= M;
    }
 
    cout << ans << '\n';
return 0;}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:69:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   69 |     for (int h = 0; h + 1 < b.size(); h++) {
      |                     ~~~~~~^~~~~~~~~~

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