P1288-取数游戏II

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 typedef long long ll;
 4 typedef double db;
 5 #define INF 0x3f3f3f3f
 6 #define _for(i,a,b) for(int i = (a);i < b;i ++)
 7 #define _rep(i,a,b) for(int i = (a);i > b;i --)
 8 
 9 inline ll read()
10 {
11     ll ans = 0;
12     char ch = getchar(), last = ' ';
13     while(!isdigit(ch)) last = ch, ch = getchar();
14     while(isdigit(ch)) ans = (ans << 1) + (ans << 3) + ch - '0', ch = getchar();
15     if(last == '-') ans = -ans;
16     return ans;
17 }
18 inline void write(ll x)
19 {
20     if(x < 0) x = -x, putchar('-');
21     if(x >= 10) write(x / 10);
22     putchar(x % 10 + '0');
23 }
24 int n;
25 int a[35];
26 int main()
27 {
28     n = read();
29     int cnt = 0;
30     bool rnt;
31     _for(i,1,n+1)
32         a[i] = read();
33     _for(i,1,n+1)
34     {
35         cnt ++;
36         if(!a[i])
37         {
38             if(cnt & 0x1)
39                 rnt = false;
40             else
41                 rnt = true;
42             break;
43         }
44     }
45     cnt = 0;
46     if(!rnt)
47     _rep(i,n,0)
48     {
49         cnt ++;
50         if(!a[i])
51         {
52             if(cnt & 0x1)
53                 rnt = false;
54             else
55                 rnt = true;
56             break;
57         }
58     }
59     if(rnt)
60         printf("YES
");
61     else
62         printf("NO
");
63     return 0;
64 }