字符串查找算法

const char* mstrstr(const char* srcstr,const char*findstr)

{

int index = 0;

assert((index = strlen(findstr) - 1) <=(strlen(srcstr) - 1));

    int i,j;

for(i = 0,j = index;srcstr[i] != 0;)

{

if(findstr[j] == srcstr[i + j])

{

if(j == 0)

{

return &srcstr[i + j];

}

--j;

}

else

{

for(;findstr[j] != srcstr[i + j];++i)

{

if(srcstr[i + j] == 0)

return NULL;

}

j = index;

}

}

return NULL;

}