Hdu 1867 KMP

 2     > File Name: 1867.cpp
 3     > Author: Stomach_ache
 4     > Mail: sudaweitong@gmail.com
 5     > Created Time: 2014年05月15日 星期四 11时24分11秒
 6     > Propose: 
 7  ************************************************************************/
 8 
 9 #include <cmath>
10 #include <string>
11 #include <cstdio>
12 #include <fstream>
13 #include <cstring>
14 #include <iostream>
15 #include <algorithm>
16 using namespace std;
17 #define MAX_N (100000+5)
18 
19 char a[MAX_N], b[MAX_N];
20 int f[MAX_N<<1];
21 void getFail(char *);
22 
23 int 
24 find (char *T, char *P) {
25       int n = strlen(T);//m = strlen(P);
26     getFail(P);
27     int j = 0;
28     for (int i = 0; i < n; i++) {
29           while (j && T[i] != P[j]) j = f[j];
30         if (P[j] == T[i]) j++;
31     }
32 
33     return j;
34 }
35 
36 void
37 getFail(char *P) {
38       int m = strlen(P);
39     f[0] = f[1] = 0;
40     for (int i = 1; i < m; i++) {
41           int j = f[i];
42         while (j && P[i] != P[j]) j = f[j];
43         f[i+1] = P[i] == P[j] ? j+1 : 0;
44     }
45 }
46 
47 int
48 main(void) {
49       while (~scanf("%s %s", a, b)) {
50         //    int len1 = strlen(a);
51         //    int len2 = strlen(b);
52             int cnt = find(a, b);
53         //    cout << cnt << endl;
54             int cnt2 = find(b, a);
55         //    cout << cnt2 << endl;
56             if (cnt > cnt2) {
57                 printf("%s", a);
58                 printf("%s\n", b+cnt);
59             } else if (cnt < cnt2){
60                 printf("%s", b);
61                 printf("%s\n", a+cnt2);
62             } else {
63                   if (strcmp(a, b) < 0) {
64                     printf("%s", a);
65                     printf("%s\n", b+cnt);
66                 } else {
67                       printf("%s", b);
68                     printf("%s\n", a+cnt2);
69                 }
70             }
71     }
72 
73     return 0;
74 }