Submission #551487

#	Time	Username	Problem	Language	Result	Execution time	Memory
551487		leaked	Skyscraper (JOI16_skyscraper)	C++17	100 / 100	358 ms	58316 KiB

skyscraper

#include <bits/stdc++.h>

#define f first
#define s second
#define m_p make_pair
#define vec vector
#define pb push_back
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
#define pw(x) (1LL<<(x))
#define sz(x) (int)(x).size()

using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
const int M=1e9+7;
void add(int &a,int b){
    a+=b;
    if(a>=M) a-=M;
    else if(a<0) a+=M;
}
int mult(int a,int b){
    return 1ll*a*b%M;
}
const int N=200+2;
const int L=1'000+2;
int dp[N][N][L][2][2];
/// памяти пизда
/// i, todel_cnt,summod,wanttodel fi,wanttodel last
signed main(){
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    int n,k;
    cin>>n>>k;
    vec<int>a(n);
    for(auto &z : a)
        cin>>z;
    sort(all(a));
    for(int t=0;t<2;t++){
        int i=0;
        int d=(i+1<n?a[i+1]-a[i]:0);
        for(int t1=0;t1<2;t1++){
            if((t+t1)*d<=k)
                dp[i+1][0][d*(t+t1)][t][t1]=1;
        }
    }
//    vec<int> how(k+1,0);
//    auto check=[&](){
//        do{
//            int s=0;
//            for(int i=1;i<n;i++)
//                s+=abs(a[i]-a[i-1]);
//            if(s<=k)
//                how[s]++;
//        }while(next_permutation(all(a)));
//    };
//    check();
//    for(auto &z : a) cout<<z<<' ';
//    cout<<endl;
    for(int i=1;i<n;i++){
        int d=(i+1<n?a[i+1]-a[i]:0);

        for(int c=0;c<=i;c++){
            for(int s=0;s<=k;s++){
                /// one middle
                for(int t=0;t<2;t++){
                    for(int t1=0;t1<2;t1++){
                        if(c){
                            if(s+2*(c-1)*d+(t+t1)*d<=k)
                                add(dp[i+1][c-1][s+2*(c-1)*d+(t+t1)*d][t][t1],mult(c,dp[i][c][s][t][t1]));
                            if(s+2*(c)*d+(t+t1)*d<=k)
                                add(dp[i+1][c][s+2*(c)*d+(t+t1)*d][t][t1],mult(c,mult(2,dp[i][c][s][t][t1])));
                            if(s+2*(c+1)*d+(t+t1)*d<=k)
                                add(dp[i+1][c+1][s+2*(c+1)*d+(t+t1)*d][t][t1],mult(c,dp[i][c][s][t][t1]));
                        }
                    }
                }
                /// first
                for(int t1=0;t1<2;t1++){
                    int t=1;
                    if(s+2*c*d+(0+t1)*d<=k)
                        add(dp[i+1][c][s+2*c*d+(0+t1)*d][0][t1],dp[i][c][s][t][t1]);
                    if(s+2*c*d+(1+t1)*d<=k)
                        add(dp[i+1][c][s+2*c*d+(1+t1)*d][1][t1],dp[i][c][s][t][t1]);

                    if(s+2*(c+1)*d+(0+t1)*d<=k)
                        add(dp[i+1][c+1][s+2*(c+1)*d+(0+t1)*d][0][t1],dp[i][c][s][t][t1]);
                    if(s+2*(c+1)*d+(1+t1)*d<=k)
                        add(dp[i+1][c+1][s+2*(c+1)*d+(1+t1)*d][1][t1],dp[i][c][s][t][t1]);
                }
                /// last
                for(int t=0;t<2;t++){
                    int t1=1;

                    if(s+2*c*d+(0+t)*d<=k)
                        add(dp[i+1][c][s+2*c*d+(t+0)*d][t][0],dp[i][c][s][t][t1]);
                    if(s+2*c*d+(1+t)*d<=k)
                        add(dp[i+1][c][s+2*c*d+(t+1)*d][t][1],dp[i][c][s][t][t1]);

                    if(s+2*(c+1)*d+(0+t)*d<=k)
                        add(dp[i+1][c+1][s+2*(c+1)*d+(t+0)*d][t][0],dp[i][c][s][t][t1]);
                    if(s+2*(c+1)*d+(1+t)*d<=k)
                        add(dp[i+1][c+1][s+2*(c+1)*d+(t+1)*d][t][1],dp[i][c][s][t][t1]);
                }
            }
        }
//        cout<<dp[2][0][2][1][0]<<endl;
    }
    int ans=0;
    for(int s=0;s<=k;s++){
//        cout<<"S "<<s<<' '<<dp[n][0][s][0][0]<<' '<<how[s]<<endl;
        add(ans,dp[n][0][s][0][0]);
    }
    cout<<ans;
    return 0;
}
/*
5 14
3 7 1 5 10
1 3 5 7 10
11 2
aa
ab
aa
ca
aa
bc
ea
aa
ad
de
aa


*/

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