FZU2275 Game（kmp

 

暑假wa的题了,,,看见vj的attempt痕迹打算挨个补了，简单kmp题，判断bob的串是不是全为0或者是alice的字串就好了

#include<algorithm>
#include<iostream>
using namespace std;
const int N = 1e6+6;
int nt[N];
string tt,ss;
bool KMP()
{
    int s = ss.size(),t = tt.size();
    if(s>t)return false;
    nt[0] = -1;
    int num = 0;
    for(int i = 0,j = -1;i < s;){
        if(j==-1||ss[i]==ss[j]){
            i++;j++;nt[i]=j;
        }
        else j = nt[j];
    } 
    for(int i = 0,j=0;i<t;){
        if(j==-1||ss[j]==tt[i]){
            i++;j++;
        }
        else j = nt[j];
        if(j==s){
            return true;
        }
    }
    return false;
}
int main()
{
    ios::sync_with_stdio(0); 
    int T;
    cin>>T;
    while(T--){
        cin>>tt>>ss;
        int ll = ss.size();
        bool flag = 0;
        for(int i = 0;i < ll;++i){
            if(ss[0]!='0')flag = 1;
        }
        if(flag==0){
            puts("Alice");continue;
        }
        for(int i = 0;i <=ll;++i)nt[i] = 0;
        if(KMP()){
            puts("Alice");continue;
        }
        reverse(ss.begin(),ss.end());
        for(int i = 0;i <=ll;++i)nt[i] = 0;
        if(KMP()){
            puts("Alice");continue;
        }
        puts("Bob");
        
    }
    return 0;
}