hnu 7/19 A Broken Audio Signal

 1 #include<iostream>
 2 #include<cstdlib>
 3 #include<cstring>
 4 #include<cstdio>
 5 using namespace std;
 6 #define ll __int64
 7 char a[1100][1100];
 8 int b[1100];
 9 int n;
10 int main(){
11     int i,j;
12     while(cin>>n &&n){
13         int t=0;
14         int f=0,o=0;
15         for(i=1;i<=n;i++){
16             cin>>a[i];
17             if(o>=2) f=1;
18             if(strstr(a[i],"x")) o++;
19             else o=0;
20             if(strstr(a[i],"x")==NULL && i!=1 && strstr(a[i-1],"x")==NULL){
21                 int k1=atoi(a[i]);
22                 int k2=atoi(a[i-1]);
23                 if(i%2==0){
24                     if(k1<=k2) f=1;
25                 }
26                 else if(k1>=k2) f=1;
27             }
28             if(strstr(a[i],"x"))
29               b[t++]=i;
30         }
31         if(f==1 || t==n){
32             cout<<"none"<<endl;
33             continue;
34         }
35         else if(t==0){
36             cout<<"ambiguous"<<endl;
37             continue;
38         }
39         ll min=-1e9-100,max=1e9+100;
40         for(i=0;i<t;i++){
41             if(b[i]%2==0){
42                 if(strstr(a[b[i]-1],"x")==NULL && b[i]-1!=0){
43                     int k=atoi(a[b[i]-1]);
44                     if(min<k)  min=k;
45                 }
46                 if(strstr(a[b[i]+1],"x")==NULL && b[i]+1<=n){
47                     int k=atoi(a[b[i]+1]);
48                     if(min<k)  min=k;
49                 }
50             }
51             else {
52                 if(strstr(a[b[i]-1],"x")==NULL && b[i]-1!=0){
53                     int k=atoi(a[b[i]-1]);
54                     if(max>k) max=k;
55                 }
56                 if(strstr(a[b[i]+1],"x")==NULL && b[i]+1<=n){
57                     int k=atoi(a[b[i]+1]);
58                     if(max>k) max=k;
59                 }
60             }
61         }
62         //cout<<"max="<<max<<"min="<<min<<endl;
63         if(max-min==2) cout<<min+1<<endl;
64         else if(max-2>min) cout<<"ambiguous"<<endl;
65         else cout<<"none"<<endl;
66     }
67     return 0;
68 }