Submission #1013998

#	Time	Username	Problem	Language	Result	Execution time	Memory
1013998		User0069	Skyscraper (JOI16_skyscraper)	C++17	100 / 100	131 ms	5200 KiB

skyscraper

#include<bits/stdc++.h>
#define taskname ""
#define el '\n'
#define fi first
#define sc second
#define pii pair<int, int>
#define all(v) v.begin(), v.end()
#define int ll
using namespace std;
using ll=long long;
using ull=unsigned long long;
using ld=long double;
#define Faster ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
using namespace std;
const int maxn=1e5+3;
const int mod=1e9+7;
const int INF=1e9+1;
int n,l,a[maxn],dp[2][103][1003][3];
signed main()
{
    if (fopen(taskname".INP","r"))
    {
        freopen(taskname".INP","r",stdin);
        freopen(taskname".OUT","w",stdout);
    }
    Faster
    cin>>n>>l;
    dp[1][1][0][0]=1;
    dp[1][1][0][2]=1;
    dp[1][1][0][1]=2;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i];
    }
    sort(a+1,a+n+1);
    for(int i=2;i<=n;i++)
    {
        int d=a[i]-a[i-1];
        for(int j=1;j<=i;j++)
        {
            for(int k=0;k<=l;k++)
            {
                for(int msk=0;msk<3;msk++)
                {
                    dp[i&1][j][k][msk]=0;
                    if(k>=(2*j-msk)*d)
                    {
                        (dp[i&1][j][k][msk]+=dp[1-(i&1)][j][k-(2*j-msk)*d][msk]*(2*j-msk))%=mod;
                    }// expand the group
                    if(msk>0&&k>=(2*j-msk+1)*d)
                    {
                        (dp[i&1][j][k][msk]+=dp[1-(i&1)][j][k-(2*j-msk+1)*d][msk-1]*(3-msk))%=mod;
                    }// stick group to the leftmost/rightmost point
                    if(k>=(2*(j-1)-msk)*d)
                    {
                        (dp[i&1][j][k][msk]+=dp[1-(i&1)][j-1][k-(2*(j-1)-msk)*d][msk]*(j-msk))%=mod;
                    }// add a new group
                    if(msk>0&&k>=(2*(j-1)-msk+1)*d)
                    {
                        (dp[i&1][j][k][msk]+=dp[1-(i&1)][j-1][k-(2*(j-1)-msk+1)*d][msk-1]*(3-msk))%=mod;
                    }// add a new group stick to the leftmost/rightmost point
                    if(k>=(2*(j+1)-msk)*d)
                    {
                        (dp[i&1][j][k][msk]+=dp[1-(i&1)][j+1][k-(2*(j+1)-msk)*d][msk]*j)%=mod;
                    }//connect 2 groups
//                    if(dp[i&1][j][k][msk]!=0) cout<<i<<" "<<j<<" "<<k<<" "<<msk<<":"<<dp[i&1][j][k][msk]<<"\n";
                }
            }
        }
    }
    int ans=0;
    for(int i=0;i<=l;i++)
    {
        (ans+=dp[n&1][1][i][2])%=mod;
    }
    cout<<ans;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:23:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   23 |         freopen(taskname".INP","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:24:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   24 |         freopen(taskname".OUT","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

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