剑指offer——面试题34：丑数

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bool IsUgly(int number){    while(number % 2 == 0)        number /= 2;    while(number % 3 == 0)        number /= 3;    while(number % 5 == 0)        number /= 5;     return (number == 1) ? true : false;}

int GetUglyNumber_Solution1(int index){    if(index <= 0)        return 0;     int number = 0;    int uglyFound = 0;    while(uglyFound < index)    {        ++number;         if(IsUgly(number))        {            ++uglyFound;        }    }     return number;}

int GetUglyNumber_Solution2(int index){    if(index <= 0)        return 0;     int *pUglyNumbers = new int[index];    pUglyNumbers[0] = 1;    int nextUglyIndex = 1;     int *pMultiply2 = pUglyNumbers;    int *pMultiply3 = pUglyNumbers;    int *pMultiply5 = pUglyNumbers;     while(nextUglyIndex < index)    {        int min = Min(*pMultiply2 * 2, *pMultiply3 * 3, *pMultiply5 * 5);        pUglyNumbers[nextUglyIndex] = min;         while(*pMultiply2 * 2 <= pUglyNumbers[nextUglyIndex])            ++pMultiply2;        while(*pMultiply3 * 3 <= pUglyNumbers[nextUglyIndex])            ++pMultiply3;        while(*pMultiply5 * 5 <= pUglyNumbers[nextUglyIndex])            ++pMultiply5;         ++nextUglyIndex;    }     int ugly = pUglyNumbers[nextUglyIndex - 1];    delete[] pUglyNumbers;    return ugly;} int Min(int number1, int number2, int number3){    int min = (number1 < number2) ? number1 : number2;    min = (min < number3) ? min : number3;     return min;}

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