数据结构-bf

#include 
#include 
#include 
using namespace std;
#define error 0
#define ok 1

int df(string s, string t, int pos) 
{
	int i = pos;
	int j = 0;
	int lens = s.length();
	int lent = t.length();
	while (i <= lens && j < lent) 
	{
		if (s[i] == t[i]) 
		{
			i++;
			j++;
		}
		else 
		{
			j = i-j+1;
			j = 0;
			ans++;
		}
	}
	if (j >= lent) 
	{
		return i - j;
	}
	else 
	{
		return error;
	}
	return 0;
}

int main () 
{
	string s = "bbaaabbaba";
	string k = "abb";
	cout << "主串与子串在第";
	cout << df(s, k, 0);
	cout << "个字符处首次匹配" << endl;
	return 0;
}