oj.uz

Submission #418929

# Submission time Handle Problem Language Result Execution time Memory
418929 2021-06-06T08:51:25 Z lyc Skyscraper (JOI16_skyscraper) C++14
100 / 100
 221 ms 130404 KB 
#include <bits/stdc++.h>
using namespace std;

#define TRACE(x) cerr << #x << " :: " << x << endl
#define _ << " " <<
#define SZ(x) (int)(x).size()
#define ALL(x) (x).begin(),(x).end()
#define FOR(i,a,b) for(int i=(a);i<=(b);++i)
#define RFOR(i,a,b) for(int i=(a);i>=(b);--i)
const int mod = 1e9+7;

const int mxN = 105;
const int mxL = 1005;
const int mxA = 1005;

int N, L, A[mxN];
int res[mxN][mxN][mxL][3];

// processing ith element, j connected component, k cost, l ends open
int dp(int i, int j, int k, int l) {
    if (k > L || l < 0) return 0;
    if (i > N) return j == 1 && l == 0;

    int& ans = res[i][j][k][l];
    if (~ans) return ans;
    ans = 0;

    int opened = 2*j - 2 + l;
    int kk = k + opened * (A[i]-A[i-1]);

    // new cc
    ans += (long long) (j+1 - 2 + l) * dp(i+1, j+1, kk, l) % mod;
    ans %= mod;
    ans += l * dp(i+1, j+1, kk, l-1) % mod;
    ans %= mod;

    if (j > 0) {
        // append
        ans += (long long) opened * dp(i+1, j, kk, l) % mod;
        ans %= mod;
        ans += l * dp(i+1, j, kk, l-1) % mod;
        ans %= mod;
    }

    if (j > 1) {
        // join
        ans += (long long) (j-1) * dp(i+1, j-1, kk, l) % mod;
        ans %= mod;
    }

    //TRACE(i _ j _ k _ l _ ans);
    return ans;
}

int main() {
    ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);

    cin >> N >> L;
    FOR(i,1,N){
        cin >> A[i];
    }

    // corner case -- cannot close both ends simultaneously
    if (N == 1) {
        cout << 1 << '\n';
        return 0;
    }

    sort(A+1,A+1+N);
    memset(res,-1,sizeof res);
    cout << dp(1,0,0,2) << '\n';
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 56 ms 130372 KB Output is correct
3 Correct 56 ms 130340 KB Output is correct
4 Correct 56 ms 130328 KB Output is correct
5 Correct 58 ms 130372 KB Output is correct
6 Correct 56 ms 130332 KB Output is correct
7 Correct 56 ms 130316 KB Output is correct
8 Correct 66 ms 130368 KB Output is correct
9 Correct 57 ms 130304 KB Output is correct
10 Correct 56 ms 130372 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 55 ms 130392 KB Output is correct
2 Correct 59 ms 130376 KB Output is correct
3 Correct 57 ms 130336 KB Output is correct
4 Correct 55 ms 130372 KB Output is correct
5 Correct 61 ms 130360 KB Output is correct
6 Correct 59 ms 130348 KB Output is correct
7 Correct 57 ms 130280 KB Output is correct
8 Correct 56 ms 130384 KB Output is correct
9 Correct 57 ms 130336 KB Output is correct
10 Correct 59 ms 130384 KB Output is correct

Subtask #3
80.0 / 80.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 56 ms 130372 KB Output is correct
3 Correct 56 ms 130340 KB Output is correct
4 Correct 56 ms 130328 KB Output is correct
5 Correct 58 ms 130372 KB Output is correct
6 Correct 56 ms 130332 KB Output is correct
7 Correct 56 ms 130316 KB Output is correct
8 Correct 66 ms 130368 KB Output is correct
9 Correct 57 ms 130304 KB Output is correct
10 Correct 56 ms 130372 KB Output is correct
11 Correct 55 ms 130392 KB Output is correct
12 Correct 59 ms 130376 KB Output is correct
13 Correct 57 ms 130336 KB Output is correct
14 Correct 55 ms 130372 KB Output is correct
15 Correct 61 ms 130360 KB Output is correct
16 Correct 59 ms 130348 KB Output is correct
17 Correct 57 ms 130280 KB Output is correct
18 Correct 56 ms 130384 KB Output is correct
19 Correct 57 ms 130336 KB Output is correct
20 Correct 59 ms 130384 KB Output is correct
21 Correct 55 ms 130372 KB Output is correct
22 Correct 221 ms 130396 KB Output is correct
23 Correct 130 ms 130392 KB Output is correct
24 Correct 137 ms 130328 KB Output is correct
25 Correct 152 ms 130380 KB Output is correct
26 Correct 120 ms 130404 KB Output is correct
27 Correct 94 ms 130364 KB Output is correct
28 Correct 108 ms 130396 KB Output is correct
29 Correct 160 ms 130372 KB Output is correct
30 Correct 136 ms 130312 KB Output is correct