经典c/c++算法

二分查找的代码.
int bfind(int* a,int len,int val)
{
    int m = len/2;
    int l = 0;
    int r = len;
    while(l!=m && r!= m)
    {
        if(a[m] > val)
        {
            r = m;
            m = (m+l)/2;
        }
        else if(a[m] < val)
        {
            l = m;
            m = (m+r)/2;
        }
        else
            return m;
    }
    return -1;   //没有找到
}
写出在母串中查找子串出现次数的代码.
int count1(char* str,char* s)
{
    char* s1;
    char* s2;
    int count = 0;
    while(*str!='\0')
    {
        s1 = str;
        s2 = s;
        while(*s2 == *s1&&(*s2!='\0')&&(*s1!='0'))
        {
            s2++;
            s1++;
        }
        if(*s2 == '\0')
            count++;
        str++;
    }
    return count;
}
出现次数相当频繁
实现