P2327 [SCOI2005]扫雷

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2

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<cmath>
 5 #include<queue>
 6 #include<algorithm>
 7 #include<cstdlib>
 8 using namespace std;
 9 const int MAXN=10001;
10 void read(int &n)
11 {
12     char c='+';int x=0,flag=1;
13     while(c<'0'||c>'9')
14     {c=getchar();if(c=='-')flag=-1;}
15     while(c>='0'&&c<='9')
16     {x=x*10+c-48;c=getchar();}
17     n=(x*flag);
18 }
19 int k=1,m,n;
20 int i,j;
21 int a[MAXN],dp[MAXN];
22 int main()
23 {
24     read(n);
25     for(i=1;i<=n;i++)
26         read(a[i]);
27     for(i=2;i<=n+1;i++)
28     {
29         dp[i]=a[i-1]-dp[i-1]-dp[i-2];
30         if(dp[i]<0||dp[i]>1)
31         {
32             k=0;
33             break;
34         }
35     }
36     if(dp[n+1]!=0)k=0;
37     m+=k;
38     memset(dp,0,sizeof(dp));
39     k=1;
40     dp[1]=1;
41     for(i=2;i<=n+1;i++)
42     {
43         dp[i]=a[i-1]-dp[i-1]-dp[i-2];
44         if(dp[i]<0||dp[i]>1)
45         {
46             k=0;
47             break;
48         }
49     }
50     if(dp[n+1]!=0)k=0;
51     m+=k;
52     printf("%d\n",m);
53     return 0;
54 }