Submission #168845

#	Time	Username	Problem	Language	Result	Execution time	Memory
168845		srvlt	Skyscraper (JOI16_skyscraper)	C++14	5 / 100	123 ms	125664 KiB

skyscraper

#include <bits/stdc++.h>

#define ll long long
#define db double
#define pb push_back
#define fi first
#define se second
#define mp make_pair
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
#define endl "\n"

//#define int long long

using namespace std;

const int N = 103, K = 1003, MOD = 1e9 + 7;
int n, r, a[N], dp[N][N][K][3];

void add(int & x, int y) {
    x += y;
    if (x >= MOD) {
        x %= MOD;
    }
}

int calc(int i, int j, int k, int l) {
    if (i > 0 && (j < 1 || l > 2 || k > r)) {
        return 0;
    }
    if (i == n) {
        return j == 1 && l == 2;
    }
    int & res = dp[i][j][k][l];
    if (res != -1) {
        return res;
    }
    int s = (a[i + 1] - a[i]) * (2 * j - l) + k;
    res = 0;
    add(res, (j + 1 - l) * calc(i + 1, j + 1, s, l));
    add(res, (2 - l) * calc(i + 1, j, s, l + 1));
    add(res, (2 - l) * calc(i + 1, j + 1, s, l + 1));
    add(res, (j - 1) * calc(i + 1, j - 1, s, l));
    add(res, (2 * j - l) * calc(i + 1, j, s, l));
    return res;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    memset(dp, -1, sizeof(dp));
    cin >> n >> r;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
    }
    if (n == 1) {
        cout << 1;
        return 0;
    }
    sort(a + 1, a + n + 1);
    a[0] = a[1];
    cout << calc(0, 0, 0, 0);
}

• Subtask 1: 5 / 5
• Subtask 2: 0 / 15
• Subtask 3: 0 / 80