Sample Input
clinton
homer
riemann
marjorie
Sample Output
0
rie 3
输入两个字符串 ，求最长相同前后缀
直接把两个字符串连接在一起求next就行了，唯一要注意的就是长度不能大于原来任一字符串的长度，如果长度大于了，要选择len1和len2中较小的一个输出。
1 # include <cstdio> 2 # include <cstring> 3 using namespace std ; 4 5 char s1[100010] ; 6 char s2[50010] ; 7 char s3[50010] ; 8 int next[100010] ; 9 int len1 , len2; 10 11 void getNext() 12 { 13 int j, k; 14 j = 0; k = -1; next[0] = -1; 15 while(j < len1+len2) 16 if(k == -1 || s1[j] == s1[k]) 17 next[++j] = ++k; 18 else 19 k = next[k]; 20 } 21 22 23 int main () 24 { 25 while (scanf("%s%s" , &s1 , &s2) != EOF) 26 { 27 len1 = strlen(s1) ; 28 len2 = strlen(s2) ; 29 strcat(s1 , s2) ; 30 getNext() ; 31 int i ; 32 for (i = 0 ; i < next[len1 + len2] ; i++) 33 { 34 s3[i] = s1[i] ; 35 } 36 s3[i] = ' ' ; 37 if (next[len1 + len2]) 38 { 39 if (next[len1 + len2] > len1 ||next[len1 + len2] > len2) 40 { 41 if (len1 > len2) 42 printf("%s %d " ,s2 ,len2) ; 43 else 44 { 45 s3[len1] = ' ' ; 46 printf("%s %d " ,s3 ,len1) ; 47 } 48 } 49 else 50 printf("%s %d " ,s3 ,next[len1 + len2]) ; 51 } 52 else 53 printf("0 ") ; 54 } 55 56 57 return 0 ; 58 }