HDU3374 字符串最大最小表示法模板

一开始没太看懂什么意思，拿笔反复推了一遍才大概知道最大最小表示法是怎么求的，感觉太神奇了...

 

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <string.h>
 4 #pragma warning ( disable : 4996 )
 5 using namespace std;
 6 
 7 inline int Max(int a,int b) { return a>b?a:b; }
 8 inline int Min(int a,int b) { return a>b?b:a; }
 9 const int inf = 0x3f3f3f3f;
10 const int maxn = 1e6+5;
11 
12 char str[maxn];
13 int nxt[maxn];
14 int len, plen, minpos, maxpos;
15 
16 void getNext()
17 {
18     memset( nxt, 0, sizeof(nxt) );
19     len = strlen(str);
20 
21     int k = -1, j = 0;
22     nxt[j] = -1;
23     
24     while ( j < len )
25     {
26         if ( k==-1 || str[j]==str[k] )
27         {
28             k++; j++;
29             nxt[j] = k;
30         }
31         else
32             k = nxt[k];
33     }
34     plen = nxt[len];
35 }
36 
37 void getMin()
38 {
39     int tmp, i = 0, j = 1, k = 0;
40     while ( i<len && j <len && k <len )
41     {
42         tmp = str[(i+k)%len]-str[(j+k)%len];
43         if(!tmp) k++;
44         else
45         {
46             if(tmp>0) i += k+1;
47             else j += k+1;
48             if( i == j ) j++;
49             k = 0;
50         }
51     }
52     minpos = i<j?i+1:j+1;
53 }
54 
55 void getMax()
56 {
57     int tmp, i = 0, j = 1, k = 0;
58     while ( i<len && j<len && k<len )
59     {
60         tmp = str[(i+k)%len]-str[(j+k)%len];
61         if(!tmp) k++;
62         else
63         {
64             if(tmp<0) i += k+1;
65             else j += k+1;
66             if( i == j ) j++;
67             k = 0;
68         }
69     }
70     maxpos = i<j?i+1:j+1;
71 }
72 
73 int main()
74 {
75     while ( ~scanf("%s", str) )
76     {
77         getNext();
78         getMin();
79         getMax();
80 
81         int tmp = (len%(len-plen)==0)?(len/(len-plen)):1;
82         printf( "%d %d %d %d\n", minpos, tmp, maxpos, tmp );
83     }
84     return 0;
85 }
View Code

 

posted @ 2018-03-23 22:33  LBNOQYX  阅读(114)  评论(0)  编辑  收藏  举报