输入一个字符串，统计其中单词的个数

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #include<ctype.h>
 4 
 5 int word_cnt(char *str);
 6 void word_print(char *str, int beg, int end);
 7 //提取单词
 8 void word_split(char *str);
 9 
10 int main()
11 {
12     char str[128];
13     //int cnt = 0;
14     gets_s(str,128);
15     //cnt = word_cnt(str);
16     //printf("count = %d
",cnt);
17     word_split(str);
18     system("pause");
19     return 0;
20 }
21 
22 int word_cnt(char *str)
23 {
24     int cnt = 0;
25     int i = 0;
26     while(str[i] != '')
27     {
28         //根据单词末尾判断
29         if(isalnum(str[i]) && (str[i+1] == ' ' || str[i+1] == ''))
30             ++cnt;
31         //根据单词开头判断
32         //if(isalnum(str[i]) && (i == 0 || i != 0 && str[i-1] == ' '))
33         ++i;
34     }
35     return cnt;
36 }
37 
38 void word_print(char *str, int beg, int end)
39 {
40     while(beg <= end)
41     {
42         putchar(str[beg]);
43         beg++;
44     }
45     printf("
");
46 }
47 
48 void word_split(char *str)
49 {
50     int cnt = 0;//记录单词的个数
51     int i = 0;//下标
52     int word_beg, word_end;//一个单词的开始、终止下标
53 
54     while(str[i] != '')
55     {
56         //找到单词的开头
57         while(str[i] && !(isalnum(str[i]) && (i== 0 || i != 0 && str[i-1] == ' ')))
58             ++i;
59         if(str[i] == '')
60             break;
61         word_beg = i;
62 
63         ++cnt;
64         //找到单词的结尾
65         while(!(isalnum(str[i]) && (str[i+1] == '' || str[i+1] == ' ')))
66             ++i;
67         word_end = i;
68         ++i;
69         printf("%dth:  ",cnt);
70         word_print(str,word_beg,word_end);
71     }
72 }