代码1（STL的map版本）
#include<iostream>
#include<map>
#include<string>
using namespace std;
int
main(int argc, char **argv)
{
map<string, int> M;
map<string, int>::iterator j;
string t;
while(cin>>t)
M[t]++;
for(j=M.begin(); j!=M.end(); ++j)
cout<<j->first<<"\t"<<j->second<<endl;
return 0;
}
代码2（自己的Hash）
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#define WORD_BUF 128
#define NHASH 29989 /* prime number just bigger than needed */
#define MULT 31
struct HNode {
char *word;
int count;
struct HNode *next;
};
struct HNode *Hash[NHASH] = {NULL};
#define NODEGROUP 1000
struct HNode *nodebuf;
int nodeleft = 0;
struct HNode *
node_alloc()
{
if(nodeleft == 0) {
nodebuf = (struct HNode *)malloc(NODEGROUP * sizeof(struct HNode));
nodeleft = NODEGROUP;
}
--nodeleft;
return (nodebuf++);
}
unsigned int
hash(char *str) /* a simple implementation of string-hash, others like ELFHash
*/
{
unsigned int ret = 0;
char *ptr;
for(ptr=str; *ptr; ++ptr)
ret = ret * MULT + (*ptr);
return (ret % NHASH);
}
void
insert_hash(char *word)
{
struct HNode *node;
unsigned int h = hash(word);
for(node=Hash[h]; node!=NULL; node=node->next)
if(strcmp(node->word, word) == 0) {
++(node->count);
return;
}
struct HNode *pend = node_alloc();
pend->word = strdup(word);
pend->count = 1;
pend->next = Hash[h];
Hash[h] = pend;
}
int
main(int argc, char **argv)
{
char buf[WORD_BUF];
while(scanf("%s", buf) != EOF) {
insert_hash(buf);
}
int i;
struct HNode *node;
for(i=0; i<NHASH; ++i)
for(node=Hash[i]; node!=NULL; node=node->next)
printf("%s\t%d\n", node->word, node->count);
return 0;
}