题目八:旋转数组的最小数字

Posted 2022-05-22 yzdai

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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;