面试题34：丑数

public class Solution {
    public int GetUglyNumber_Solution(int index) {
        if(index<=0) return 0;
        
        int[] uglyNumbers=new int[index];
        uglyNumbers[0]=1;
        int num=1;
        int mutiply2=0,mutiply3=0,mutiply5=0;
        
        while(num<index){
            uglyNumbers[num]=min(uglyNumbers[mutiply2]*2,uglyNumbers[mutiply3]*3,uglyNumbers[mutiply5]*5);
            if(uglyNumbers[mutiply2]*2==uglyNumbers[num])
                mutiply2++;
            if(uglyNumbers[mutiply3]*3==uglyNumbers[num])
                mutiply3++; 
            if(uglyNumbers[mutiply5]*5==uglyNumbers[num])
                mutiply5++;
            num++;
        }
        return uglyNumbers[index-1];
        
    }
    public int min(int n1,int n2,int n3){
        int min=(n1<n2)?n1:n2;
        min=(min<n3)?min:n3;
        return min;
    }
}