字符串匹配之朴素匹配

 1 # include<iostream>
 2 # include<cstdio>
 3 # include<string>
 4 using namespace std;
 5 int index(char *a,char *b)
 6 {
 7     int n=0;//父串偏移量，初始为0
 8     while(a[n]!=‘\0‘)
 9     {
10         int m = n;
11         int k; //子串偏移量
12         for(k = 0; b[k]!=‘\0‘; k++)
13         {
14             if(a[m++]!=b[k]) //不匹配，马上停止
15             {
16                 break;
17             }
18         }
19         if(b[k]==‘\0‘)//匹配成功
20         {
21             return n;
22         }
23         n++;//父串，开始移动
24     }
25     return -1;
26 }
27 int main()
28 {
29     char *a = "abcdef";
30     char *b = "cdef";
31     cout<<index(a,b)<<endl;
32 }