LeetCode(264):Ugly Number II

Posted 2020-06-18

Ugly Number II:Write a program to find the n-th ugly number.Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. For example, 1, 2, 3, 4, 5, 6, 8, 9, 10, 12 is the sequence of the first 10 ugly numbers.Note that 1 is typically treated as an ugly number.

题意：找出第n个丑数。

代码：

public class Solution {
    public int nthUglyNumber(int n) {
        int[] uglyNums = new int[n];
        int next = 1;
        int i=0,j=0,k=0;
        uglyNums[0] = 1;
        while(next<n){
            int min = MinT(uglyNums[i]*2,uglyNums[j]*3,uglyNums[k]*5);
            uglyNums[next] = min;
                if(uglyNums[i]*2 == min) i++;
            if(uglyNums[j]*3 == min) j++;
            if(uglyNums[k]*5 <= min) k++;
            next++;
        }
        return uglyNums[n-1];
    }
    public int MinT(int t1,int t2,int t3){
        int min = t1<t2?t1:t2;
        return min<t3?min:t3;
        
    }
}