void KmpMatcher(char* t,char* p)
{
int* w;
int lent;
int lenp;
int i,q;
lent=strlen(t);
lenp=strlen(p);
w=ComputePrefix(p);
q=0;
for(i=0;i<lent;i++)
{
while(q>0&&p[q]!=t[i])
{
q=w[q-1];
}
if(p[q]==t[i])
{
q++;
}
if(q==lenp)
{
printf("find string whith shift %d\n",i-lenp+1);
q=w[q-1];
}
}
}
int KMP(const char* text, const char* pattern)
{
int text_len = strlen(text);
int pattern_len = strlen(pattern);
if(pattern_len == 0)// "",""
{
return 0;
}
if(text_len < pattern_len)//"", "a"
{
return -1;
}
int *prefix_value = new int[pattern_len+1]();//记得初始化！
ComputePrefix(pattern, prefix_value);
int last_prefix_value = 0;
for(int i = 0; i < text_len; i++)
{
int text_index = i+last_prefix_value;
int j = last_prefix_value;//已知匹配的位不用再次匹配！
for(; j < pattern_len; j++)
{
if(text_index < text_len && text[text_index] == pattern[j])
{
text_index++;
}
else
{
break;
}
}
if(j == pattern_len)
{
delete[] prefix_value;
return i;
}
else if(j > 0)
{
i += j-prefix_value[j]-1;//注意在此移动的位数要先减1,因为后面还有i++;
last_prefix_value = prefix_value[j];//记录最大公共长度，方便以后计算比较位！
}
}
delete[] prefix_value;
return -1;
}
