【KMP】hdu 1867(A+B for you again)杭電java a題真坑

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Problem Description
Generally speaking, there are a lot of problems about strings processing. Now you encounter another such problem. If you get two strings, such as “asdf” and “sdfg”, the result of the addition between them is “asdfg”, for “sdf” is the tail substring of “asdf” and the head substring of the “sdfg” . However, the result comes as “asdfghjk”, when you have to add “asdf” and “ghjk” and guarantee the shortest string first, then the minimum lexicographic second, the same rules for other additions.
 
Input
For each case, there are two strings (the chars selected just form ‘a’ to ‘z’) for you, and each length of theirs won’t exceed 10^5 and won’t be empty.
 
Output
Print the ultimate string by the book.
 
Sample Input

   
   
   
   

    
    
    
    asdf sdfg
asdf ghjk
   
   
   
   

 
Sample Output

   
   
   
   

    
    
    
    asdfg
asdfghjk
   
   
   
   

問題の構想を解く:問題は文字列のモードが一致して、いくつかの細部の問題に注意すればいいです.でもjavaが書いてあるのは無限超メモリで、今日は気分が悪くて、また渡して、過ぎて、これは無言ですね.

import java.util.*;
class P1867{
    static int[] next=new int[100005];
    public static void main(String args[]){
        int n,m,i,len1,len2;
        String str1,str2;
        Scanner sc=new Scanner(System.in);
        while(sc.hasNext()){
            str1=sc.next();
            str2=sc.next();
            len1=str1.length();
            len2=str2.length();
            n=kmp(str1,str2);
            m=kmp(str2,str1);
            if(n==m){
                if(str1.compareTo(str2)>0){
                    System.out.println(str2+str1.substring(n,len1));
                }else{
                    System.out.println(str1+str2.substring(n,len2));
                }
            }else if(n>m){
                System.out.println(str1+str2.substring(n,len2));
            }else{
                System.out.println(str2+str1.substring(m,len1));
            }
        }
    }
    public static void set_next(String str){
        int i=0,j=-1;
        next[0]=-1;
        int len=str.length();
        while(i<len){
            if(j==-1||str.charAt(i)==str.charAt(j)){
                i++;
                j++;
                next[i]=j;///System.out.print(next[i]+" ");
            }else{
                j=next[j];
            }
        }
        //System.out.println();
    }
    public static int kmp(String str1,String str2){
        int i=0,j=0;
        int len1=str1.length(),len2=str2.length();
        set_next(str2);
        while(i<len1){//System.out.print(j+" ");
            if(j==-1||(j<len2&&str1.charAt(i)==str2.charAt(j))){
                i++;
                j++;//System.out.print("** ");
            }else{
                j=next[j];
            }//System.out.print(j+"* ");
        }//System.out.println();
        if(i==len1){
            return j;
        }
        return 0;
    }
}