http://acm.hdu.edu.cn/showproblem.php?pid=1880
最初的想法直接快排+二分查找
为了练习hash就用hash做了
View Code
1 #include <cstdio> 2 #include <cstring> 3 using namespace std; 4 5 const int N=100010,MAXH=100003; 6 char w0[N][25],w1[N][85]; 7 int head[2][MAXH],next[2][N]; 8 int n; 9 int hash(char *key) 10 { 11 unsigned int h=0; 12 while(*key) 13 { 14 h=(h<<4)+*key++; 15 unsigned int g=h&0xf000000L; 16 if(g) h^=g>>24; 17 h&=~g; 18 } 19 return h%MAXH; 20 } 21 void insert(int s,int k) 22 { 23 int h=k?hash(w1[s]):hash(w0[s]); 24 next[k][s]=head[k][h]; 25 head[k][h]=s; 26 } 27 void dictionary() 28 { 29 const char end[6]="@END@"; 30 memset(head,0,sizeof(head)); 31 memset(next,0,sizeof(next)); 32 n=0; 33 char s1[25],s2[85]; 34 while(scanf("%s",s1),strcmp(s1,end)) 35 { 36 n++; 37 strcpy(w0[n],s1); 38 insert(n,0); 39 getchar(); gets(s2); 40 strcpy(w1[n],s2); 41 insert(n,1); 42 } 43 } 44 int find(char *s,int k) 45 { 46 int h=hash(s); 47 int u=head[k][h]; 48 if(k==0) while(u && strcmp(s,w0[u])) u=next[k][u]; 49 else while(u && strcmp(s,w1[u])) u=next[k][u]; 50 return u; 51 } 52 void putstr(char *s) 53 { 54 for(int i=1;s[i]!=']';i++) putchar(s[i]); 55 putchar('\n'); 56 } 57 int main() 58 { 59 dictionary(); 60 int T; 61 scanf("%d",&T); getchar(); 62 while(T--) 63 { 64 char s[85]; 65 gets(s); 66 if(s[0]=='[') 67 { 68 int p=find(s,0); 69 if(p) puts(w1[p]); 70 else puts("what?"); 71 } 72 else 73 { 74 int p=find(s,1); 75 if(p) putstr(w0[p]); 76 else puts("what?"); 77 } 78 } 79 return 0; 80 }
