HDU 1022 - Train Problem I

 1 #include <iostream>
 2 #include <string>
 3 using namespace std;
 4 int n,cnt,cnt2;
 5 char s1[100000],s2[100000],a[100000];
 6 string ans;
 7 int main()
 8 {
 9     while(~scanf("%d%s%s",&n,&s1,&s2))
10     {
11         ans.clear();//这行很要紧 
12         bool flag=1;
13         cnt2=cnt=0;
14         int i=0;
15         while(i<n)
16         {
17             if(cnt && a[cnt-1]==s2[cnt2])
18             {
19                 ans+="out\n";
20                 cnt--;
21                 cnt2++;
22             } else {
23                 a[cnt++]=s1[i++];
24                 ans+="in\n";            
25             }
26         }
27         while(cnt2<n)
28         {
29             if(s2[cnt2]!=a[cnt-1]){
30                 flag=0; break;
31             } else {
32                 ans+="out\n";
33                 cnt--;
34                 cnt2++;
35             }
36         }
37         if(flag){
38             puts("Yes.");
39             cout<<ans;
40         } else {
41             puts("No.");
42         }
43         puts("FINISH");
44     }
45 }//2016-04-22 23:07:08