题目八:旋转数组的最小数字

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//12. 题目八:旋转数组的最小数字

int RotatedBinarySearchMinNum(int aiArray[], int iLen)
{
    int iLeft = 0;
    int iMid = 0;
    int iRight = iLen - 1;

    while (aiArray[iLeft] >= aiArray[iRight])
    {
        if (iRight - iLeft == 1)
        {
            iMid = iRight;
            break;
        }

        iMid = iLeft + (iRight - iLeft) / 2;
        if (aiArray[iMid] >= aiArray[iLeft])
        {
            iLeft = iMid;
        }
        else if (aiArray[iMid] <= aiArray[iRight])
        {
            iRight = iMid;
        }
    }

    return aiArray[iMid];
}

// 旋转数组中查找
int RotatedBinarySearch(int aiArray[], int iLen, int iTarget)
{
    int iLeft = 0;
    int iMid = 0;
    int iRight = iLen - 1;

    while (iLeft <= iRight)
    {
        iMid = iLeft + (iRight - iLeft) / 2;
        if (aiArray[iMid] == iTarget)
        {
            return iMid;
        }

        // 情况一：旋转点在中位数的右侧
        if (aiArray[iMid] >= aiArray[iLeft])
        {
            // 最左侧元素 <= 查找目标 < 中位数
            if (aiArray[iLeft] <= iTarget && iTarget < aiArray[iMid])
            {
                iRight = iMid - 1;
            }
            else
            {
                iLeft = iMid + 1;
            }
        }
        // 情况二: 旋转点在中位数的左侧
        else
        {
            // 中位数 < 查找目标 <= 最右侧元素
            if (aiArray[iMid] < iTarget && iTarget <= aiArray[iRight])
            {
                iLeft = iMid + 1;
            }
            else
            {
                iRight = iMid - 1;
            }
        }
    }

    return -1;
}

void RotatedBinarySearchTestFunc()
{
    cout << "\n\n --------------- RotatedBinarySearchTestFunc Start -------------->" << endl;
    int aiArray[] = {9, 10, 11, 12, 13, 1, 3, 4, 5, 8};
    int iLen = sizeof(aiArray) / sizeof(int);
    TRAVERSAL_ARRAY(aiArray, iLen);

    cout << "旋转数组中最小数字: " << RotatedBinarySearchMinNum(aiArray, iLen) << endl;

    int iFindNum = 5;
    int iIndex = RotatedBinarySearch(aiArray, iLen, iFindNum);
    if (iIndex > 0)
    {
        printf("Find %02d[%02d] Success!", iFindNum, iIndex);
    }
    else
    {
        cout << "Find: " << iFindNum << " Failed!" << endl;
    }

    cout << "\n\n --------------- RotatedBinarySearchTestFunc Start -------------->" << endl;

}

原文地址：https://www.cnblogs.com/yzdai/p/11258624.html