Submission #1164954

#	Time	Username	Problem	Language	Result	Execution time	Memory
1164954		hainam2k9	Skyscraper (JOI16_skyscraper)	C++20	100 / 100	48 ms	19468 KiB

skyscraper

#include <bits/stdc++.h>
#define tt cin.tie(0), cout.tie(0), ios_base::sync_with_stdio(0)
#define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
#define ll long long
#define ull unsigned long long
#define i128 __int128
#define db long double
#define sz(a) ((int)(a).size())
#define pb emplace_back
#define pf emplace_front
#define pob pop_back
#define pof pop_front
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define ins emplace
#define mp make_pair
using namespace std;
const int MOD = 1e9+7, MAXN = 1e5+5;
const string NAME = "";
int n,k,a[105],dp[105][105][1005][2][2],rs=0;
inline void add(int &a, int b){
    a+=b;
    if(a>=MOD) a-=MOD;
}
int main()
{
    tt;
    if(fopen((NAME + ".INP").c_str(), "r")) fo;
    cin >> n >> k;
    for(int i = 1; i<=n; ++i)
        cin >> a[i];
    if(n==1) return cout << 1, 0;
    sort(a+1,a+n+1);
    dp[1][1][0][0][0]=dp[1][1][0][0][1]=dp[1][1][0][1][0]=1;
    for(int i = 1; i<n; ++i)
        for(int j = 1; j<=i; ++j)
            for(int sum = 0; sum<=k; ++sum)
                for(int l = 0; l<2; ++l)
                    for(int r = 0; r<2; ++r){
                        if(!dp[i][j][sum][l][r]) continue;
                        int newsum=sum+(j*2-l-r)*(a[i+1]-a[i]);
                        if(newsum>k) continue;
                        add(dp[i+1][j][newsum][l][r],1ll*(j*2-l-r)*dp[i][j][sum][l][r]%MOD);
                        add(dp[i+1][j+1][newsum][l][r],1ll*(j+1-l-r)*dp[i][j][sum][l][r]%MOD);
                        if(j>=2) add(dp[i+1][j-1][newsum][l][r],1ll*(j-1)*dp[i][j][sum][l][r]%MOD);
                        if(l==0) add(dp[i+1][j][newsum][l|1][r],dp[i][j][sum][l][r]), add(dp[i+1][j+1][newsum][l|1][r],dp[i][j][sum][l][r]);
                        if(r==0) add(dp[i+1][j][newsum][l][r|1],dp[i][j][sum][l][r]), add(dp[i+1][j+1][newsum][l][r|1],dp[i][j][sum][l][r]);
                    }
    for(int sum = 1; sum<=k; ++sum) add(rs,dp[n][1][sum][1][1]);
    cout << rs;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:3:19: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    3 | #define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
      |            ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:30:45: note: in expansion of macro 'fo'
   30 |     if(fopen((NAME + ".INP").c_str(), "r")) fo;
      |                                             ^~
skyscraper.cpp:3:63: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    3 | #define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
      |                                                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:30:45: note: in expansion of macro 'fo'
   30 |     if(fopen((NAME + ".INP").c_str(), "r")) fo;
      |                                             ^~

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