HNU 12812 Broken Audio Signal

题目链接：http://acm.hnu.cn/online/?action=problem&type=show&id=12812

一直弄错了一个题意，教训啊，比赛最怕的就是弄错题意了

 #include<cstdio>
 #include<iostream>
 #include<algorithm>
 #include<cstring>
 #include<cmath>
 #include<cstdlib>
 using namespace std;
 const int maxn = +;
 int num[maxn],X[maxn],flag[maxn];

 int main()
 {
 //    freopen("A2.out","w",stdout);
 //    freopen("A.in","r",stdin);
     int n;
     char str[];
     while(scanf("%d",&n),n)
     {
         memset(flag,,sizeof(flag));
         int num_x = ,end = ;
         for(int i = ;i <= n;++i)
         {
             scanf("%s",str);
             if(str[] == 'X' || str[] == 'x')
             {
                 flag[i] = ;
                 X[num_x++] = i;
             }
             else num[i] = atoi(str);
             if(i >  && flag[i] ==  && flag[i-] == )
             end = ;
         }
         if(num_x >= n || end)   /////全是x无法判断,超过两个x在一起也是无解
         {
             printf("none\n");
             continue;
         }
         for(int i = ;i < n;++i)
         if(flag[i] ==  && flag[i+] == )
         {
             if(((i & ) && num[i] >= num[i+]) || (!(i & ) && num[i] <= num[i+]))
             {
                 end = ;
                 break;
             }
         }
         if(end)        /////出现不符合规则的情况
         {
             printf("none\n");
             continue;
         }
         int l = -0x7fffffff,r = 0x7fffffff;
         for(int i = ;i < num_x;++i)
         if(X[i] & )
         {
             if(X[i] >  && flag[X[i]-] == )
             r = min(r,num[X[i]-] - );
             if(X[i] < n && flag[X[i]-] == )
             r = min(r,num[X[i]+] - );
         }
         else
         {
             if(X[i] >  && flag[X[i]-] == )
             l = max(l,num[X[i]-] + );
             if(X[i] < n && flag[X[i]+] == )
             l = max(l,num[X[i]+] + );
         }
         if(l == r)
         printf("%d\n",l);
         else if(l > r)
         printf("none\n");
         else printf("ambiguous\n");
     }
     return ;
 }