Glass Beads
Time Limit: 3000ms
Memory Limit: 131072KB
This problem will be judged on UVALive. Original ID: 5545
64-bit integer IO format: %lld Java class name: Main
Once upon a time there was a famous actress. As you may expect, she played mostly Antique Comedies most of all. All the people loved her. But she was not interested in the crowds. Her big hobby were beads of any kind. Many bead makers were working for her and they manufactured new necklaces and bracelets every day. One day she called her mainInspector of Bead Makers (IBM) and told him she wanted a very long and special necklace.
The necklace should be made of glass beads of different sizes connected to each other but without any thread running through the beads, so that means the beads can be disconnected at any point. The actress chose the succession of beads she wants to have and the IBM promised to make the necklace. But then he realized a problem. The joint between two neighbouring beads is not very robust so it is possible that the necklace will get torn by its own weight. The situation becomes even worse when the necklace is disjoined. Moreover, the point of disconnection is very important. If there are small beads at the beginning, the possibility of tearing is much higher than if there were large beads. IBM wants to test the robustness of a necklace so he needs a program that will be able to determine the worst possible point of disjoining the beads.
The description of the necklace is a string 
specifying sizes of the particular beads, where the last character am is considered to precede character a1 in circular fashion.
The disjoint point i is said to be worse than the disjoint point j if and only if the string 
is lexicografically smaller than the string 
. String 
is lexicografically smaller than the string 
if and only if there exists an integer 
, so that aj=bj, for each 
and ai < bi.
Input
The input consists of N cases. The first line of the input contains only positive integer N. Then follow the cases. Each case consists of exactly one line containing necklace description. Maximal length of each description is 10000 characters. Each bead is represented by a lower-case character of the english alphabet (a-z), where 
.
Output
For each case, print exactly one line containing only one integer - number of the bead which is the first at the worst possible disjoining, i.e. such i, that the string A[i] is lexicographically smallest among all the n possible disjoinings of a necklace. If there are more than one solution, print the one with the lowest i.
Sample Input
4 helloworld amandamanda dontcallmebfu aaabaaa
Sample Output
10 11 6 5
Source
Regionals 1998, Europe - Central
解题；耍耍SAM，看不懂构建的原理，奶奶个熊
1 #include <bits/stdc++.h>
2 using namespace std;
3 const int maxn = 100010;
4 struct SAM {
5 struct node {
6 int son[26],f,len;
7 void init() {
8 f = -1;
9 len = 0;
10 memset(son,-1,sizeof son);
11 }
12 } sn[maxn<<1];
13 int tot,last;
14 void init() {
15 tot = last = 0;
16 sn[tot++].init();
17 }
18 int newnode() {
19 sn[tot].init();
20 return tot++;
21 }
22 void extend(int c) {
23 int np = newnode(),p = last;
24 sn[np].len = sn[last].len + 1;
25 while(p != -1 && sn[p].son[c] == -1) {
26 sn[p].son[c] = np;
27 p = sn[p].f;
28 }
29 if(p == -1) sn[np].f = 0;
30 else {
31 int q = sn[p].son[c];
32 if(sn[p].len + 1 == sn[q].len) sn[np].f = q;
33 else {
34 int nq = newnode();
35 sn[nq] = sn[q];
36 sn[nq].len = sn[p].len + 1;
37 sn[np].f = sn[q].f = nq;
38 while(p != -1 && sn[p].son[c] == q) {
39 sn[p].son[c] = nq;
40 p = sn[p].f;
41 }
42 }
43 }
44 last = np;
45 }
46 } sam;
47 char str[maxn];
48 int main() {
49 int kase;
50 scanf("%d",&kase);
51 while(kase--) {
52 sam.init();
53 scanf("%s",str);
54 int len = strlen(str),p = 0;
55 for(int i = 0; i < (len<<1); ++i) {
56 sam.extend(str[i%len]-‘a‘);
57 }
58 for(int i = 0; i < len; ++i) {
59 for(int j = 0; j < 26; ++j) {
60 if(sam.sn[p].son[j] != -1) {
61 p = sam.sn[p].son[j];
62 break;
63 }
64 }
65 }
66 printf("%d\n",sam.sn[p].len - len + 1);
67 }
68 return 0;
69 }
70 /*
71 4
72 helloworld
73 amandamanda
74 dontcallmebfu
75 aaabaaa
76 */