pat 1077 Kuchiguse(20 分) (字典树)
1077 Kuchiguse(20 分)
The Japanese language is notorious for its sentence ending particles. Personal preference of such particles can be considered as a reflection of the speaker's personality. Such a preference is called "Kuchiguse" and is often exaggerated artistically in Anime and Manga. For example, the artificial sentence ending particle "nyan~" is often used as a stereotype for characters with a cat-like personality:
-
Itai nyan~ (It hurts, nyan~)
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Ninjin wa iyada nyan~ (I hate carrots, nyan~)
Now given a few lines spoken by the same character, can you find her Kuchiguse?
Input Specification:
Each input file contains one test case. For each case, the first line is an integer N (2≤N≤100). Following are N file lines of 0~256 (inclusive) characters in length, each representing a character's spoken line. The spoken lines are case sensitive.
Output Specification:
For each test case, print in one line the kuchiguse of the character, i.e., the longest common suffix of all N lines. If there is no such suffix, writenai
.
Sample Input 1:
3
Itai nyan~
Ninjin wa iyadanyan~
uhhh nyan~
Sample Output 1:
nyan~
Sample Input 2:
3
Itai!
Ninjinnwaiyada T_T
T_T
Sample Output 2:
nai
1 #include <iostream> 2 #include <algorithm> 3 #include <cstdio> 4 #include <cstring> 5 #include <string> 6 #include <map> 7 #include <stack> 8 #include <vector> 9 #include <queue> 10 #include <set> 11 #define LL long long 12 #define INF 0x3f3f3f3f 13 using namespace std; 14 const int MAX = 1e5 + 10; 15 16 int n, rt = 0, str_len = INF; 17 struct node 18 { 19 int id, cnt, next[128]; 20 } P[MAX]; 21 char shortest_str[300]; 22 stack <char> st; 23 24 void init(int x) 25 { 26 for (int i = 0; i <= 127; ++ i) 27 P[x].next[i] = -1; 28 } 29 30 void my_insert(char *S, int len, int x) 31 { 32 int now = 0; 33 for (int i = 0; i < len; ++ i) 34 { 35 if (P[now].next[S[i]] == -1) 36 { 37 P[now].next[S[i]] = ++ rt; 38 init(rt); 39 } 40 now = P[now].next[S[i]]; 41 P[now].cnt ++; 42 } 43 } 44 45 int my_find(int len) 46 { 47 int now = 0; 48 for (int i = 0; i < len; ++ i) 49 { 50 if (P[now].next[shortest_str[i]] == -1) return -1; 51 now = P[now].next[shortest_str[i]]; 52 } 53 return P[now].cnt; 54 } 55 56 int main() 57 { 58 // freopen("Date1.txt", "r", stdin); 59 scanf("%d", &n); 60 init(0); 61 getchar(); 62 for (int i = 0; i < n; ++ i) 63 { 64 char buf[300]; 65 string temp; 66 getline(cin, temp); 67 int len = temp.size(); 68 for (int j = 0, k = len - 1; k >= 0; -- k, ++ j) 69 buf[j] = temp[k]; 70 buf[len] = '\0'; 71 my_insert(buf, len, i); 72 if (len < str_len) 73 { 74 str_len = len; 75 strcpy(shortest_str, buf); 76 } 77 } 78 79 if (P[P[0].next[shortest_str[0]]].cnt != n) 80 { 81 printf("nai\n"); 82 return 0; 83 } 84 for (int i = str_len; i >= 1; -- i) 85 { 86 if (my_find(i) == n) 87 { 88 for (int j = 0; j < i; ++ j) 89 st.push(shortest_str[j]); 90 break; 91 } 92 } 93 while (st.size()) 94 { 95 printf("%c", st.top()); 96 st.pop(); 97 } 98 99 return 0; 100 }