POJ_1200_Crazy Search

时间：2014-10-26 21:11:14 阅读：326 评论：0 收藏：0 [点我收藏+]

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1. 题目描述

给一个长串，找出不重复的，长度为nc的字串数目。

2. 代码示例

  1 /*
  2 Source Code
  3 
  4 Problem: 1200        User: robinho364
  5 Memory: 40504K        Time: 63MS
  6 Language: G++        Result: Accepted
  7 */
  8 #define _USE_MATH_DEFINES
  9 
 10 #ifdef ONLINE_JUDGE
 11 #define FINPUT(file) 0
 12 #define FOUTPUT(file) 0
 13 #else
 14 #define FINPUT(file) freopen(file,"r",stdin)
 15 #define FOUTPUT(file) freopen(file,"w",stdout)
 16 #endif
 17 
 18 #include <iostream>
 19 #include <cstdio>
 20 #include <cstring>
 21 #include <cstdlib>
 22 #include <cmath>
 23 #include <ctime>
 24 #include <set>
 25 #include <stack>
 26 #include <string>
 27 #include <map>
 28 #include <vector>
 29 #include <queue>
 30 #include <algorithm>
 31 #include <functional>
 32 
 33 typedef long long ll;
 34 static const int N = 16000010;
 35 static const int M = 20;
 36 static const int LEN = 100;
 37 static const int MAX = 0x7fffffff;
 38 static const int GMAX = 0x3f3f3f3f;
 39 static const int MIN = ~MAX;
 40 static const double EPS = 1e-7;
 41 static const int BASE = 10000007;
 42 static const int CH = 27;
 43 char str[N];
 44 int hash[BASE];
 45 int char_to_num[257];
 46 
 47 bool inline cmp(int i, int j, int n)
 48 {
 49     int res = strncmp(str + i, str + j, n);
 50     if (res) {
 51         return false;
 52     } else {
 53         return true;
 54     }
 55 }
 56 
 57 void inline rabin_karp(int n, int nc, int len)
 58 {
 59     int seed = 0;
 60     for(int i = 0;i<len;i++){
 61         if(char_to_num[str[i]] == 0){
 62             char_to_num[str[i]] = ++seed;
 63         }
 64     }
 65 
 66     int t = 1;
 67 
 68     for(int i = 0;i<n;i++)
 69         t*=nc;
 70 
 71     int ah = 0;
 72 
 73     for(int i = 0;i<n;i++)
 74         ah = (ah*nc + char_to_num[str[i]]) % BASE;
 75 
 76     int ncount = 0;
 77     for(int i = 0;i+n<=len;i++){
 78         if(!hash[ah]){
 79             hash[ah] = i + 1;
 80             ncount++;
 81         } else {
 82             int res = ah;
 83             while (hash[res] && !cmp(i, hash[res] - 1, n)) {
 84                 res = (res + 1) % BASE;
 85             }
 86             hash[res] = i + 1;
 87         }
 88         if(i+n<len){
 89             ah = (ah*nc + char_to_num[str[i+n]] - char_to_num[str[i]]*t)%BASE;
 90         }
 91     }
 92 
 93     printf("%d\n", ncount);
 94 }
 95 
 96 int main()
 97 {
 98     FINPUT("in.txt");
 99     FOUTPUT("out.txt");
100 
101     int n, nc;
102     while (scanf("%d %d", &n, &nc) != EOF) {
103         scanf("%s", str);
104         memset(char_to_num, 0, sizeof(char_to_num));
105         memset(hash, false, sizeof(hash));
106         rabin_karp(n, nc + 1, strlen(str));
107     }
108 
109     return 0;
110 }

source code

 1 /*
 2 Source Code
 3 
 4 Problem: 1200        User: robinho364
 5 Memory: 17008K        Time: 32MS
 6 Language: G++        Result: Accepted
 7 */
 8 #define _USE_MATH_DEFINES
 9 
10 #ifdef ONLINE_JUDGE
11 #define FINPUT(file) 0
12 #define FOUTPUT(file) 0
13 #else
14 #define FINPUT(file) freopen(file,"r",stdin)
15 #define FOUTPUT(file) freopen(file,"w",stdout)
16 #endif
17 
18 #include <iostream>
19 #include <cstdio>
20 #include <cstring>
21 #include <cstdlib>
22 #include <cmath>
23 #include <ctime>
24 #include <set>
25 #include <stack>
26 #include <string>
27 #include <map>
28 #include <vector>
29 #include <queue>
30 #include <algorithm>
31 #include <functional>
32 
33 typedef long long ll;
34 static const int N = 16000010;
35 static const int M = 20;
36 static const int LEN = 100;
37 static const int MAX = 0x7fffffff;
38 static const int GMAX = 0x3f3f3f3f;
39 static const int MIN = ~MAX;
40 static const double EPS = 1e-7;
41 static const int BASE = 6000011;
42 static const int CH = 27;
43 char str[N];
44 bool hash[N];
45 int char_to_num[257];
46 
47 void inline rabin_karp(int n, int nc, int len)
48 {
49     int seed = 0;
50     for(int i = 0;i<len;i++){
51         if(char_to_num[str[i]] == 0){
52             char_to_num[str[i]] = ++seed;
53         }
54     }
55 
56     int t = 1;
57 
58     for(int i = 0;i<n;i++)
59         t*=nc;
60 
61     int ah = 0;
62 
63     for(int i = 0;i<n;i++)
64         ah = ah*nc + char_to_num[str[i]];
65 
66     int ncount = 0;
67     for(int i = 0;i+n<=len;i++){
68         if(hash[ah] == false){
69             hash[ah] = true;
70             ncount++;
71         }
72         if(i+n<len){
73             ah = ah*nc + char_to_num[str[i+n]] - char_to_num[str[i]]*t;
74         }
75     }
76 
77     printf("%d\n", ncount);
78 }
79 
80 int main()
81 {
82     FINPUT("in.txt");
83     FOUTPUT("out.txt");
84 
85     int n, nc;
86     while (scanf("%d %d", &n, &nc) != EOF) {
87         scanf("%s", str);
88         memset(char_to_num, 0, sizeof(char_to_num));
89         memset(hash, false, sizeof(hash));
90         rabin_karp(n, nc + 1, strlen(str));
91     }
92 
93     return 0;
94 }