Submission #308912

#	Time	Username	Problem	Language	Result	Execution time	Memory
308912		arnold518	Skyscraper (JOI16_skyscraper)	C++14	100 / 100	409 ms	383116 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], S[MAXN+10];
 
ll dp[110][110][1010][4];
 
ll solve(int pos, int comp, int val, int state)
{
 	int t=A[pos]-A[pos-1];
 	val+=(comp*2-state)*t;
 	if(val<0) return 0;

	if(val>L) return 0;
	if(pos==N+1)
	{
		if(comp==1 && state==2) return 1;
		else return 0;
	}
	ll &ret=dp[pos][comp][val][state];
	if(ret!=-1) return ret;
 
	ret=0;
	ret+=(comp+1-state)*solve(pos+1, comp+1, val, state);
	if(comp>=1) ret+=(comp*2-state)*solve(pos+1, comp, val, state);
	if(comp>=2) ret+=(comp-1)*solve(pos+1, comp-1, val, state);
	if(state==1)
	{
		ret+=solve(pos+1, comp, val, state+1);
		ret+=solve(pos+1, comp+1, val, state+1);
	}
	else if(state==0)
	{
		ret+=2*solve(pos+1, comp, val, state+1);
		ret+=2*solve(pos+1, comp+1, val, state+1);
	}
	ret%=MOD;
	//printf("%d %d %d %d : %lld\n", pos, comp, val, state, ret);
 
	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);
	A[0]=A[1];
 
	memset(dp, -1, sizeof(dp));
	printf("%lld\n", solve(1, 0, 0, 0));
	//printf("!%d %d\n", v1, v2);
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:52:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   52 |  scanf("%d%d", &N, &L);
      |  ~~~~~^~~~~~~~~~~~~~~~
skyscraper.cpp:54:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   54 |  for(int i=1; i<=N; i++) scanf("%d", &A[i]);
      |                          ~~~~~^~~~~~~~~~~~~

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