Submission #601714

#	Time	Username	Problem	Language	Result	Execution time	Memory
601714		1bin	Skyscraper (JOI16_skyscraper)	C++14	100 / 100	198 ms	121004 KiB

skyscraper

#include <bits/stdc++.h>

using namespace std;

#define all(v) v.begin(), v.end()
typedef long long ll;
const ll mod = 1e9 + 7;
ll n, mx, dp[105][105][1005][5], h[101];

int main(void){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    
    cin >> n >> mx;
    for(int i = 1; i <= n; i++) cin >> h[i];
    if(n == 1){
        cout << "1"; return 0;
    }
    sort(h + 1, h + n + 1);
    dp[0][0][0][0] = 1; h[n + 1] = 10000;
    for(int i = 1; i <= n; i++)
        for(int j = 1; j <= i; j++)
            for(int kk = 0; kk <= mx; kk++)
                for(int l = 0; l < 3; l++){
                    int d = (2 * j - l) * (h[i + 1] - h[i]);
                    int k = kk + d;
                    if(k > mx) continue;
                    if(j > l) dp[i][j][k][l] += (j - l) * dp[i - 1][j - 1][kk][l];
                    dp[i][j][k][l] += (2 * j - l) * dp[i - 1][j][kk][l];
                    dp[i][j][k][l] += j * dp[i - 1][j + 1][kk][l];
                    if(l) {
                        dp[i][j][k][l] += (3 - l) * dp[i - 1][j - 1][kk][l - 1];
                        if(i == 2 && j == 1 && k == 5 && l == 1){
                            //cout << i << ' ' << j << ' ' << kk << ' ' << l - 1 << ' ' << dp[i][j][kk][l - 1] << '\n';      
                        }
                        dp[i][j][k][l] += (3 - l) * dp[i - 1][j][kk][l - 1];
                    }
                    dp[i][j][k][l] %= mod;
                    //cout << i << ' ' << j << ' ' << k << ' ' << l << ' ' << dp[i][j][k][l] << '\n';
                }
    ll ans = 0;
    for(int i = 0; i <= mx; i++) ans += dp[n][1][i][2], ans %= mod;
    cout << ans;
    return 0;
}

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