Submission #1013960

#	Time	Username	Problem	Language	Result	Execution time	Memory
1013960		BackNoob	Real Mountains (CCO23_day1problem2)	C++14	25 / 25	1400 ms	88676 KiB

Main

#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define endl '\n'
#define MASK(i) (1LL << (i))
#define ull unsigned long long
#define ld long double
#define pb push_back
#define all(x) (x).begin() , (x).end()
#define BIT(x , i) ((x >> (i)) & 1)
#define TASK "task"
#define sz(s) (int) (s).size()
 
using namespace std;
const int mxN = 1e6 + 227;
const int inf = 1e9 + 277;
const int mod = 1e6 + 3;
const ll infll = 1e18 + 7;
const int base = 307;
const int LOG = 20;
 
template <typename T1, typename T2> bool minimize(T1 &a, T2 b) {
    if (a > b) {a = b; return true;} return false;
}
template <typename T1, typename T2> bool maximize(T1 &a, T2 b) {
    if (a < b) {a = b; return true;} return false;
}

struct Segtree{
    int n;
    vector<int> t;
    Segtree(){}
    Segtree(int _n) {
        n = _n;
        int offset = 1; 
        while(offset <= n) offset *= 2;
        t.resize(offset * 2 + 7, inf);
    }

    void update(int v, int tl, int tr, int pos, int val) {
        if(tl == tr) {
            t[v] = val;
        }
        else {
            int tm = (tl + tr) / 2;
            if(pos <= tm) update(v * 2, tl, tm, pos, val);
            else update(v * 2 + 1, tm + 1, tr, pos, val);
            t[v] = min(t[v * 2], t[v * 2 + 1]);
        }
    }

    int getmin(int v, int tl, int tr, int l, int r) {
        if(l > r) return inf;
        if(tl == l && tr == r) return t[v];
        int tm = (tl + tr) / 2;
        int m1 = getmin(v * 2, tl, tm, l, min(r, tm));
        int m2 = getmin(v * 2 + 1, tm + 1, tr, max(l, tm + 1), r);
        return min(m1, m2);
    }

    void update(int pos, int val) {
        update(1, 1, n, pos, val);
    }
    int getmin(int l, int r) {
        return getmin(1, 1, n, l, r);
    }
} seg;

int n;
int a[mxN];
int b[mxN];

int getsum(int l, int r) {
    if(l > r) return 0;
    return (1LL * (r + l) * (r - l + 1) / 2) % mod;
}

void add(int &a, int b) {
    a += b;
    if(a >= mod)
        a -= mod;
}
 
void solve()
{
    cin >> n;
    for(int i = 1; i <= n; i++) cin >> a[i];

    vector<pair<int, int>> order;
    for(int i = 1; i <= n; i++) order.pb({a[i], i});
    sort(all(order));


    int mx = *max_element(a + 1, a + n + 1);
    int p = -1;
    for(int i = 1; i <= n; i++) if(a[i] == mx) p = i;

    int curmax = -1;
    for(int i = 1; i <= p; i++) {
        maximize(curmax, a[i]);
        b[i] = curmax;
    }
    curmax = -1;
    for(int i = n; i >= p; i--) {
        maximize(curmax, a[i]);
        b[i] = curmax;
    }

    vector<pair<int, int>> order2;
    for(int i = 1; i <= n; i++) if(a[i] != b[i]) {
        order2.pb({b[i], i});
    }
    sort(all(order2));


    
    seg = Segtree(n);
    for(int i = 1; i <= n; i++) seg.update(i, a[i]);

    int res = 0;
    int j = 0;
    p = 0;
    set<int> s;
    while(p < sz(order)) {
        int nxt = p;
        while(nxt < sz(order) && order[p].fi == order[nxt].fi) {
            seg.update(order[nxt].se, inf);
            if(a[order[nxt].se] != b[order[nxt].se]) s.insert(order[nxt].se);
            ++nxt;
        }

        int curval = order[p].fi;
        p = nxt;
        // for(auto it : s) cout << it << ' ';
        // cout << endl;

        while(j < sz(order2) && order2[j].fi == curval) {
            s.erase(s.find(order2[j].se));
            ++j;
        }

        if(sz(s) == 0) continue;


        if(sz(s) > 1) {
            int p1 = *s.begin();
            int p2 = *--s.end();

            int l1 = seg.getmin(1, p1 - 1);
            int r1 = seg.getmin(p1 + 1, n);

            int l2 = seg.getmin(1, p2 - 1);
            int r2 = seg.getmin(p2 + 1, n);

            // cout << l1 << ' ' << r1 << ' ' << l2 << ' ' << r2 << endl;

            int minval = min({l1, r1, l2, r2});
            if(r1 <= l2) {
                add(res, getsum(curval, minval - 1));
                add(res, 1LL * l1 * (minval - curval) % mod);
                add(res, 1LL * r1 * (minval - curval) % mod);


                add(res, getsum(curval, minval - 1));
                add(res, getsum(curval + 1, minval));
                add(res, 1LL * r2 * (minval - curval) % mod);

            }
            else {
                add(res, getsum(curval, minval - 1));
                add(res, 1LL * l2 * (minval - curval) % mod);
                add(res, 1LL * r2 * (minval - curval) % mod);
                // cout << res << endl;

                add(res, getsum(curval, minval - 1));
                add(res, 1LL * l1 * (minval - curval) % mod);
                add(res, getsum(curval + 1, minval));
            }

            add(res, 2LL * getsum(curval + 1, minval) % mod * (sz(s) - 2) % mod);
            add(res, 1LL * (sz(s) - 2) * getsum(curval, minval - 1) % mod);
        }
        else {
            int p1 = *s.begin();

            int l1 = seg.getmin(1, p1 - 1);
            int r1 = seg.getmin(p1 + 1, n); 
            // cout << l1 << ' ' << r1 << endl;
            int minval = min(l1, r1);
            add(res, getsum(curval, minval - 1));
            add(res, 1LL * l1 * (minval - curval) % mod);
            add(res, 1LL * r1 * (minval - curval) % mod);
        }


    }
    

    cout << res;
}
 
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

 
    int tc = 1;
    //cin >> tc;
    while(tc--) {
        solve();
    }
    return 0;
}

• 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