Match:Blue Jeans(POJ 3080)

Posted 2020-06-13

　　　　　　　　　　　　　　　　

　　　　　　　　　　　　　　　　　　DNA序列

　　题目大意：给你m串字符串，要你找最长的相同的连续字串

　　这题暴力kmp即可，注意要按字典序排序，同时，是len<3才输出no significant commonalities

　　

  1 #include <iostream>
  2 #include <functional>
  3 #include <algorithm>
  4 #include <string.h>
  5 #define MAX 60
  6 
  7 using namespace std;
  8 
  9 typedef char* _String;
 10 typedef int Position;
 11 static char str[11][61],ans[62];
 12 static int _next[62];
 13 
 14 bool KmpSearch(_String, _String, const int);
 15 void Get_Next(_String, const int);
 16 void Search(const int);
 17 
 18 int main(void)//暴力枚举第一行
 19 {
 20     int case_sum, m;
 21     //freopen("in.txt", "r", stdin);
 22     scanf("%d", &case_sum);
 23 
 24     while (case_sum--)
 25     {
 26         scanf("%d", &m);
 27         getchar();
 28         
 29         for (int i = 0; i < m; i++)
 30             scanf("%s", str[i]);
 31         Search(m);
 32     }
 33     return EXIT_SUCCESS;
 34 }
 35 
 36 void Search(const int m)
 37 {
 38     int len, ans_len = -1, pos, if_match;
 39     char tmp;
 40 
 41     for (len = 1; len <= MAX; len++)
 42     {
 43         for (pos = 0; pos + len <= MAX; pos++)
 44         {
 45             if_match = 0;
 46             Get_Next(&str[0][pos], len);
 47             for (int i = 1; i < m; i++)
 48                 if_match += KmpSearch(str[i], &str[0][pos], len);
 49             if (if_match == m - 1 && len >= ans_len)
 50             {
 51                 if (len == ans_len)
 52                 {
 53                     tmp = str[0][pos + len];
 54                     str[0][pos + len] = ‘\0‘;
 55                     if (strcmp(&str[0][pos], ans) < 0)
 56                         strcpy(ans, &str[0][pos]);
 57                     str[0][pos + len] = tmp;
 58                 }
 59                 else if (len > ans_len)
 60                 {
 61                     ans_len = len;
 62                     tmp = str[0][pos + len];
 63                     str[0][pos + len] = ‘\0‘;
 64                     strcpy(ans, &str[0][pos]);
 65                     str[0][pos + len] = tmp;
 66                 }
 67             }
 68         }
 69     }
 70     if (ans_len < 3)
 71         printf("no significant commonalities\n");
 72     else
 73         printf("%s\n", ans);
 74 }
 75 
 76 bool KmpSearch(_String str_m, _String text, const int t_len)
 77 {
 78     Position i = 0, j = 0;
 79 
 80     while (i < MAX && j < t_len)
 81     {
 82         if (j == -1 || str_m[i] == text[j])
 83         {
 84             i++;
 85             j++;
 86         }
 87         else j = _next[j];
 88     }
 89     if (j == t_len)
 90         return true;
 91     else
 92         return false;
 93 }
 94 
 95 void Get_Next(_String text, const int t_len)
 96 {
 97     Position i = 0, k = -1;
 98     _next[0] = -1;
 99 
100     while (i < t_len)
101     {
102         if (k == -1 || text[i] == text[k])
103         {
104             i++;
105             k++;
106             _next[i] = text[i] != text[k] ? k : _next[k];
107         }
108         else k = _next[k];
109     }
110 }