二分查找

没啥好说的，只是要注意防止m = (r + l) / 2;时m会发生上溢。

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template <class T>
int BSearch(T *a, size_t n, T v)
{
    assert(a != NULL && n > 0); //! a == NULL || n <= 0 就坏了:-(
    size_t l = 0,
           r = n -1,
           m = l + (r - l) / 2; //! 勿用m=(l+r)/2;
    while(l <= r)
    {
        if(a[m] == v) 
            return (int)m;
        else if(a[m] < v)
            l = m + 1;
        else
            r = m - 1;
    }
    return -1;
}
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Filed under: 边走编程 By dutor @ August 24th, 2009, 10 views Comments (4)
你好！除了代码，此处没有多少原创之物，皆为本人搜集、整理、总结之记录与心得，欢迎转载分享！转载时请尽量注明出处，将不胜感激。祝你健康、快乐！
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