https://www.jisuanke.com/contest/7332/386137
思路:仔细观察,发现我们要做的就是将a与b匹配(就像括号一样)并允许c移到任何地方

#include <bits/stdc++.h>
using namespace std;
stack<char> mystack;
bool fun(string s)
{
   
    for(int i=0; i<s.size(); i++) {
   
        if(s[i]=='a')
            mystack.push('a');
        else if(s[i]=='b') {
   
            if(mystack.empty())
                return false;
            else
                mystack.pop();
        }
        else if(s[i]!='c')
            return false;
    }
    return mystack.empty();
}
int main()
{
   
    int n;
    scanf("%d", &n);
    for(int k=1; k<=n; k++)
    {
   
        string s;
        cin>>s;
        while(!mystack.empty() )
            mystack.pop();
        if(fun(s))
            printf("Pattern %d: More aliens!\n",k);
        else
            printf("Pattern %d: Still Looking.\n",k);
        if(k!=n)
            printf("\n");
    }
    return 0;
}