Submission #963273

#	Time	Username	Problem	Language	Result	Execution time	Memory
963273		noobcodur	Skyscraper (JOI16_skyscraper)	C++14	20 / 100	231 ms	186036 KiB

skyscraper

#include<bits/stdc++.h>
using namespace std;

using ld = long double;

#define int long long
#define pii pair<int,int>
#define forn(i,j) for(int i = 0; i < j; ++i)
#define forrange(i,j,k) for(int i = j; i < k; ++i)
#define vi vector<int>
#define vpii vector<pii>
#define f first
#define s second
#define pb push_back
#define all(x) x.begin(),x.end()

const int MOD = 1e9+7; const int INF = 1e17+1; const int maxN = 2e5+1;

void setIO(string name){
	ios_base::sync_with_stdio(0);
	cin.tie(0);

	if(!name.empty()){
		freopen((name + ".in").c_str(),"r",stdin);
		freopen((name + ".out").c_str(),"w",stdout);
	}
}

int a[14];
vector<vector<vi>> dp;

signed main(){
	setIO("");
	int n,L;
	cin >> n >> L;

	dp = vector<vector<vi>>((1 << n),vector<vi>(n,vi(L+1))); 

	forn(i,n){
		cin >> a[i];
	}

	int res = 0;

	forrange(mask,1,1 << n){
		forn(i,n){
			if(!(mask & (1 << i))) continue;

			if(__builtin_popcount(mask) == 1){
				dp[mask][i][0] = 1;

				continue;
			}

			forn(j,n){
				if(!(mask & (1 << j)) || j == i) continue;

				int dist = abs(a[i]-a[j]);
				forn(l,L-dist+1){
					int mask2 = mask - (1 << i);

					dp[mask][i][l+dist] += dp[mask2][j][l];
					dp[mask][i][l+dist] %= MOD;
				}
			}
		}
	}

	forn(i,n){
		forn(l,L+1){
			res += dp[(1 << n)-1][i][l];
			res %= MOD;
		}
	}

	cout << res << endl;
}

Compilation message (stderr)

skyscraper.cpp: In function 'void setIO(std::string)':
skyscraper.cpp:24:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   24 |   freopen((name + ".in").c_str(),"r",stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:25:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |   freopen((name + ".out").c_str(),"w",stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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