c++经典案例

C/C++ 经典算法实例2009-03-04 19:11二分查找的代码.
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;
}

查找第一个匹配子串位置,如果返回的是s1长度len1表示没有找到
size_t find(char* s1,char* s2)
    {
        size_t i=0;
         size_t len1 = strlen(s1)
        size_t len2 = strlen(s2);
        if(len1-len2<0) return len1;
        for(;i        {
            size_t m = i;
            for(size_t j=0;j            {
                if(s1[m]!=s2[j])
                    break;
                m++;