Submission #973637

#	Time	Username	Problem	Language	Result	Execution time	Memory
973637		8pete8	Skyscraper (JOI16_skyscraper)	C++17	100 / 100	49 ms	27548 KiB

skyscraper

#include<iostream>
#include<stack>
#include<map>
#include<vector>
#include<string>
#include<unordered_map>
#include <queue>
#include<cstring>
#include<limits.h>
#include <cassert>
#include<cmath>
#include<set>
#include<algorithm>
#include <iomanip>
#include<numeric> //gcd(a,b)
#include<bitset>
#include <cstdlib> 
#include <cstdint>
using namespace std;
#define ll long long
#define f first
//#define endl "\n"
#define s second
#define pii pair<int,int>
#define ppii pair<int,pii>
#define vi vector<int>
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define F(n) for(int i=0;i<n;i++)
#define lb lower_bound
#define ub upper_bound
#define fastio ios::sync_with_stdio(false);cin.tie(NULL);
#pragma GCC optimize ("03,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
using namespace std;
#define int long long
#define double long double
const int mod=1e9+7,mxn=1e5+5,lg=60,inf=1e9,minf=-1e18,Mxn=1e6+50000;
int dp[103][103][1002][3];
int32_t main(){
	fastio
	//dp[i][num of com][cur sum][border have]
	int n,l;cin>>n>>l;
	vector<int>v(n);
	for(int i=0;i<n;i++)cin>>v[i];
	sort(all(v));
	v.pb(v.back());
	int nsum;
	if(n==1){
		cout<<1;
		return 0;
	}
	if(2*(v[1]-v[0]))dp[1][1][2*(v[1]-v[0])][0]=1;
	if(v[1]-v[0]<=l)dp[1][1][v[1]-v[0]][1]=2;
	for(int i=1;i<n;i++){
		for(int j=1;j<=n;j++){
			for(int sum=0;sum<=l;sum++){
				for(int k=0;k<3;k++){
					if(dp[i][j][sum][k]==0)continue;
					//cout<<dp[i][j][sum][k]<<" "<<i<<" "<<j<<" "<<sum<<" "<<k<<" "<<"G\n";
					//create
					nsum=(sum+((v[i+1]-v[i])*((j+1)*2-k)));
					if(nsum<=l&&nsum>=0){
						dp[i+1][j+1][nsum][k]=(dp[i+1][j+1][nsum][k]+(dp[i][j][sum][k]*(j+1-k))%mod)%mod;
					}
					//merge
					nsum=(sum+((v[i+1]-v[i])*((j-1)*2-k)));
					if(nsum<=l&&nsum>=0)dp[i+1][j-1][nsum][k]=(dp[i+1][j-1][nsum][k]+(dp[i][j][sum][k]*(j-1))%mod)%mod;
					//fill border
					//fill border by creating new one
					nsum=(sum+((v[i+1]-v[i])*(((j+1)*2)-k-1)));
					if(nsum<=l&&nsum>=0&&k+1<3){
						dp[i+1][j+1][nsum][k+1]=(dp[i+1][j+1][nsum][k+1]+(dp[i][j][sum][k]*(2-k))%mod)%mod;
					}
					/*
					missing case where
					a>b<c
					*/
					//fill border by attaching to the existing one
					nsum=(sum+(v[i+1]-v[i])*((j*2)-k-1));
					if(nsum<=l&&nsum>=0&&k+1<3){
						dp[i+1][j][nsum][k+1]=(dp[i+1][j][nsum][k+1]+(dp[i][j][sum][k]*(2-k))%mod)%mod;
					}
					//attach
					nsum=(sum+(v[i+1]-v[i])*((j*2)-k));
					if(nsum<=l&&nsum>=0)dp[i+1][j][nsum][k]=(dp[i+1][j][nsum][k]+(dp[i][j][sum][k]*((j-k)*2+k))%mod)%mod;//stick it
				}				
			}
		}
	}
	int ans=0;
	for(int i=0;i<=l;i++){
		//cout<<dp[n][1][i][2]<<" "<<i<<'\n';
		ans=(ans+dp[n][1][i][2])%mod;
	}
	cout<<ans;
	/*
	*/
	return 0;
}
/*
*/

Compilation message (stderr)

skyscraper.cpp: In function 'int32_t main()':
skyscraper.cpp:54:6: warning: '*' in boolean context, suggest '&&' instead [-Wint-in-bool-context]
   54 |  if(2*(v[1]-v[0]))dp[1][1][2*(v[1]-v[0])][0]=1;
      |     ~^~~~~~~~~~~~

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