Submission #101166

#	Time	Username	Problem	Language	Result	Execution time	Memory
101166		autumn_eel	Skyscraper (JOI16_skyscraper)	C++14	20 / 100	321 ms	91128 KiB

skyscraper

#include <bits/stdc++.h>
#define rep(i,n)for(int i=0;i<(n);i++)
#define MOD 1000000007
#define INF 0x3f3f3f3f
using namespace std;
typedef long long ll;
typedef pair<int,int>P;

int dp[1<<14][14][101];
int a[14];

int main(){
	int n,L;cin>>n>>L;
	if(n>14)abort();
	rep(i,n)scanf("%d",&a[i]);
	if(n<=8){
		vector<int>v;
		rep(i,n)v.push_back(i);
		int ans=0;
		do{
			int cnt=0;
			rep(i,v.size()-1){
				(cnt+=abs(a[v[i]]-a[v[i+1]]));
			}
			if(cnt<=L)ans++;
		}while(next_permutation(v.begin(),v.end()));
		cout<<ans<<endl;
		return 0;
	}
	rep(i,n)dp[1<<i][i][0]=1;
	rep(i,1<<n)rep(j,n){
		if(!(i>>j&1))continue;
		rep(k,L+1){
			if(dp[i][j][k]==0)continue;
			rep(t,n){
				if(i>>t&1)continue;
				if(abs(a[t]-a[j])+k<=L){
					(dp[i|1<<t][t][abs(a[t]-a[j])+k]+=dp[i][j][k])%=MOD;
				}
			}
		}
	}
	int ans=0;
	rep(i,n)rep(j,L+1)(ans+=dp[(1<<n)-1][i][j])%=MOD;
	cout<<ans<<endl;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:2:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 #define rep(i,n)for(int i=0;i<(n);i++)
                              ^
skyscraper.cpp:22:4: note: in expansion of macro 'rep'
    rep(i,v.size()-1){
    ^~~
skyscraper.cpp:15:15: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  rep(i,n)scanf("%d",&a[i]);
          ~~~~~^~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 0 / 80