Leetcode OJ Ugly number II (Ugly-two)

Topic:

Write a program to find the n -th ugly number.

ugly numbers is positive numbers whose prime factors only Include 2, 3, 5 . For Example, 1, 2, 3, 4, 5, 6, 8, 9, ten,  is the sequence of the First 10  ugly numbers.

Note that's 1 typically treated as an ugly number.

Ideas:

Reference: http://blog.csdn.net/u012243115/article/details/45222269.

Code:

Class Solution {public:    int nthuglynumber (int n)     {        if (n <= 0)            return 0;        int *uglynum = new Int[n] ();        int *uglynum2 = Uglynum;        int *uglynum3 = Uglynum;        int *uglynum5 = Uglynum;        Uglynum[0] = 1;        int count = 1;        while (Count < n)        {            int curugly = min (min (*uglynum2 * 2, *UGLYNUM3 * 3), *UGLYNUM5 * 5);            Uglynum[count] = curugly;            while (*UGLYNUM2 * 2 <= curugly)                uglynum2++;            while (*UGLYNUM3 * 3 <= curugly)                uglynum3++;            while (*UGLYNUM5 * 5 <= curugly)                uglynum5++;            count++;        }        int result = Uglynum[n-1];        delete [] uglynum;        return result;}            ;

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Leetcode OJ Ugly number II (Ugly-two)