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AlgorithmLearning-二分查找

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二分查找法

示例

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//返回一组数中某个数的索引
int BinarySearch(List<int> list, int target)
{
    int low = 0;
    int high = list.Count - 1;
    while (low <= high)
    {
        int mid = (low + high) / 2;
        int tmp = list[mid];
        if(tmp == target)
            return mid;
        if(tmp > target)
            high = mid - 1;
        else
            low = mid + 1;
    }
    return -1;
}

int pos = BinarySearch(new List<int>{1, 3, 5, 7, 9}, 3);//1