Submission #1037127

#	Time	Username	Problem	Language	Result	Execution time	Memory
1037127		Shayan86	Skyscraper (JOI16_skyscraper)	C++14	100 / 100	57 ms	79444 KiB

skyscraper

#include <bits/stdc++.h>
using namespace std;

#pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
// Ofast, O0, O1, O2, O3, unroll-loops, fast-math, trapv

typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;

#define Mp          make_pair
#define sep         ' '
#define endl        '\n'
#define F	        first
#define S	        second
#define pb          push_back
#define SZ(x)       (int)x.size()
#define all(x)      (x).begin(),(x).end()
#define kill(res)	cout << res << '\n', exit(0);
#define set_dec(x)	cout << fixed << setprecision(x);
#define fast_io     ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define file_io     freopen("input.txt", "r", stdin) ; freopen("output.txt", "w", stdout);

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const ll N = 109;
const ll M = 1009;
const ll Mod = 1e9 + 7;

ll n, L, a[N], dp[N][N][M][3];

int main(){
    fast_io;
    
    cin >> n >> L;

    for(int i = 1; i <= n; i++) cin >> a[i];
    a[n+1] = 2e4;

    sort(a+1, a+n+1);

    if(n == 1) kill(1);

    dp[1][1][2*(a[2]-a[1])][0] = 1;
    dp[1][1][a[2]-a[1]][1] = 2;

    for(int i = 2; i <= n; i++){
        for(int j = 1; j <= i; j++){
            for(int k = 0; k <= L; k++){
                for(int o = 0; o < 3; o++){
                    int dist = (a[i+1] - a[i]) * (2*j - o);
                    if(k < dist) continue;

                    dp[i][j][k][o] += (j-o) * dp[i-1][j-1][k-dist][o];
                    if(o) dp[i][j][k][o] += (3-o) * dp[i-1][j-1][k-dist][o-1];
                    dp[i][j][k][o] += (2*j-o) * dp[i-1][j][k-dist][o];
                    if(o) dp[i][j][k][o] += (3-o) * dp[i-1][j][k-dist][o-1];
                    dp[i][j][k][o] += j * dp[i-1][j+1][k-dist][o];

                    dp[i][j][k][o] %= Mod;
                }
            }
        }
    }

    ll res = 0;
    for(int k = 0; k <= L; k++) res += dp[n][1][k][2];
    res %= Mod;

    cout << res;

}

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