Submission #308895

#	Time	Username	Problem	Language	Result	Execution time	Memory
308895		arnold518	Skyscraper (JOI16_skyscraper)	C++14	0 / 100	295 ms	524292 KiB

skyscraper

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

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int MAXN = 100;
const ll MOD = 1e9+7;

int N, L, A[MAXN+10];

ll dp[110][110][5000][4];

ll solve(int pos, int comp, int val, int state)
{
	if(pos==N+1)
	{
		if(comp==1 && 0<=val && val<=L && state==3) return 1;
		else return 0;
	}
	ll &ret=dp[pos][comp][val+2000][state];
	if(ret!=-1) return ret;

	ret=0;
	int sz=__builtin_popcount(state);

	ret+=(comp+1-sz)*solve(pos+1, comp+1, val-2*A[pos], state);
	ret+=(comp*2-sz)*solve(pos+1, comp, val, state);
	if(comp) ret+=(comp-1)*solve(pos+1, comp-1, val+2*A[pos], state);
	if((state&1)==0) ret+=solve(pos+1, comp, val+A[pos], state|1);
	if((state&1)==0) ret+=solve(pos+1, comp+1, val-A[pos], state|1);
	if((state&2)==0) ret+=solve(pos+1, comp, val+A[pos], state|2);
	if((state&2)==0) ret+=solve(pos+1, comp+1, val-A[pos], state|2);
	//printf("%d %d %d %d : %lld\n", pos, comp, val, state, ret);
	ret%=MOD;
	return ret;
}

int main()
{
	scanf("%d%d", &N, &L);
	if(N==1) return !printf("1");
	for(int i=1; i<=N; i++) scanf("%d", &A[i]);
	sort(A+1, A+N+1);

	memset(dp, -1, sizeof(dp));
	printf("%lld\n", solve(1, 0, 0, 0));
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:42:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   42 |  scanf("%d%d", &N, &L);
      |  ~~~~~^~~~~~~~~~~~~~~~
skyscraper.cpp:44:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   44 |  for(int i=1; i<=N; i++) scanf("%d", &A[i]);
      |                          ~~~~~^~~~~~~~~~~~~

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