Luogu P2327 [SCOI2005]扫雷【递推/数学】By cellur925

 1 #include<cstdio>
 2 #include<algorithm>
 3 #include<cstring>
 4 #define maxn 10090
 5 
 6 using namespace std;
 7 
 8 int n,ans;
 9 int fir[maxn],sec[maxn];
10 
11 bool check()
12 {
13     for(int i=3;i<=n+1;i++)
14         fir[i]=sec[i-1]-fir[i-2]-fir[i-1];
15     if(fir[n+1]) return false;
16     return true;
17 }
18 
19 int main()
20 {
21     scanf("%d",&n);
22     for(int i=1;i<=n;i++) scanf("%d",&sec[i]);
23     for(int k=0;k<=sec[1];k++)
24     {
25         memset(fir,0,sizeof(fir));
26         fir[1]=k;
27         fir[2]=sec[1]-k;
28         if(check()) ans++;
29     }
30     printf("%d",ans);
31     return 0;
32 }