Submission #1215078

#	Time	Username	Problem	Language	Result	Execution time	Memory
1215078		stefanneagu	Flooding Wall (BOI24_wall)	C++20	0 / 100	0 ms	328 KiB

Main

#include <bits/stdc++.h>
#define int long long

using namespace std;

const int nmax = 1e5 + 1, mod = 1e9 + 7;

struct str {
    int a, b;
} v[nmax];

vector<pair<int, int>> bag;
int pref[nmax][2];
int suf[nmax][2];
int pw[nmax];
bool f[nmax];

/*
int p2[nmax];
int i2[nmax];

int fast(int N, int E) {
    int ans = 1;
    while (E) {
        if (E & 1) {
            ans = (ans * N) % mod;
        }
        N = (N * N) % mod;
    }
    return ans;
}

void pre() {
    p2[0] = 1;
    for (int i = 1; i < nmax; i++) {
        p2[i] = (2 * p2[i - 1]) % mod;
    }
    i2[nmax - 1] = fast(p2[nmax - 1], mod - 2);
    for (int i = nmax - 2; i >= 0; i--) {
        i2 = (2 * i2[i + 1]) % mod;
    }
} */

void pwb(int n) {
    for (int i = 1; i <= n; i++) {
        pw[i] = 2;
    }
}

int32_t main() {
    // pre();
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int n;
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> v[i].a;
    }
    for (int i = 1; i <= n; i++) {
        cin >> v[i].b;
        if (v[i].a < v[i].b) {
            swap(v[i].a, v[i].b);
        }
        bag.push_back({v[i].a, i});
        bag.push_back({v[i].b, i});
    }
    sort(bag.begin(), bag.end(), greater<pair<int, int>>());
    pwb(n);
    int ind = 0;
    while (ind < bag.size()) {
        vector<pair<int, int>> cr;
        cr.push_back(bag[ind++]);
        while (ind < bag.size() && cr.back().first == bag[ind].first) {
            cr.push_back(bag[ind++]);
        }
        for (auto [nr, i] : cr) {
            pref[i][f[i]] = 1;
            for (int j = i - 1; j >= 1; j--) {
                pref[i][f[i]] = (pref[i][f[i]] * pw[j]) % mod;
            }
            suf[i][f[i]] = 1;
            for (int j = i + 1; j <= n; j++) {
                suf[i][f[i]] = (suf[i][f[i]] * pw[j]);
            }
            f[i] = 1;
        }
        for (auto [nr, i] : cr) {
            pw[i]--;
        }
    }
    sort(bag.begin(), bag.end());
    int ans = 0;
    pwb(n);
    ind = 0;
    for (auto [nr, i] : bag) {
        // negativ
        int sp = 0, ss = 0;
        int prod = 1;
        for (int j = i - 1; j >= 1; j--) {
            if (v[j].a >= nr) {
                sp = (sp + prod * pref[j][0]) % mod;
            }
            if (v[j].b >= nr) {
                sp = (sp + prod * pref[j][1]) % mod;
            }
            prod = (prod * pw[j]) % mod;
        }
        prod = 1;
        for (int j = i + 1; j <= n; j++) {
            if (i == 1) {
                cout << i << " " << j << ": " << prod * suf[j][0] << " " << prod * suf[j][0] << '\n';
            }
            if (v[j].a >= nr) {
                ss = (ss + prod * suf[j][0]) % mod;
            }
            if (v[j].b >= nr) {
                ss = (ss + prod * suf[j][1]) % mod;
            }
            prod = (prod * pw[j]) % mod;
        }
        pw[i]--;
        ans -= (ss * sp) * nr;
        cout << i << ": " << ss << " " << sp <<  '\n';
        // cout << "?? " << i << ": " << ss * sp << '\n';
    }
    cout << "\n\n\n";
    pwb(n);
    for (int i = 1; i <= n; i++) {
        f[i] = 0;
    }
    sort(bag.begin(), bag.end(), greater<pair<int, int>>());
    for (auto [nr, i] : bag) {
        // pozitiv
        int sp = 0;
        int prod = pw[i - 1];
        for (int j = i - 2; j >= 1; j--) {
            if (v[j].a >= nr) {
                sp = (sp + prod * pref[j][0] * (i - j - 1)) % mod;
            }
            if (v[j].b >= nr) {
                sp = (sp + prod * pref[j][1] * (i - j - 1)) % mod;
            }
            prod = (prod * pw[j]) % mod;
        }
        int ss = 0;
        prod = pw[i + 1];
        for (int j = i + 2; j <= n; j++) {
            if (v[j].a > nr) {
                ss = (ss + prod * suf[j][0] * (j - i - 1)) % mod;
            }
            if (v[j].b > nr) {
                ss = (ss + prod * suf[j][1] * (j - i - 1)) % mod;
            }
            prod = (prod * pw[j]) % mod;
        }
        ans += (ss * pref[i][f[i]] + sp * suf[i][f[i]]) * nr;
        cout << i << ": " << ss << " " << sp << '\n';
        f[i] = 1;
        pw[i]--;
    }
    cout << ans;
    return 0;
}

• Subtask 1: 0 / 8
• Subtask 2: 0 / 17
• Subtask 3: 0 / 19
• Subtask 4: 0 / 14
• Subtask 5: 0 / 12
• Subtask 6: 0 / 30