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Super Ugly Number: Write a program to find the nth super ugly number.Super ugly numbers are positive numbers whose all prime factors are in the given prime list primes of size k. For example, [1, 2, 4, 7, 8, 13, 14, 16, 19, 26, 28, 32] is the sequence of the first 12 super ugly numbers given primes = [2, 7, 13, 19] of size 4.
Note:
(1) 1 is a super ugly number for any given primes.
(2) The given numbers in primes are in ascending order.
(3) 0 < k ≤ 100, 0 < n ≤ 106, 0 < primes[i] < 1000.
题意：给定因子Primes,求第n个Super ugly number。
思路：和Ugly Number II 思路一样，不过这次要使用一个优先队列实现。
代码：
public class Solution { public int nthSuperUglyNumber(int n, int[] primes) { int[] ugly_number = new int[n]; ugly_number[0] = 1; PriorityQueue<Node> q = new PriorityQueue<Node>(); for(int i=0;i<primes.length;i++) q.add(new Node(0,primes[i],primes[i])); for(int i=1;i<n;i++){ Node cur = q.peek(); ugly_number[i] = cur.val; do{ cur = q.poll(); cur.val = ugly_number[++cur.index]*cur.prime; q.add(cur); }while(!q.isEmpty()&&q.peek().val==ugly_number[i]); } return ugly_number[n - 1]; } class Node implements Comparable<Node>{ int index; int val; int prime; Node(int index,int val,int prime){ this.val = val; this.index = index; this.prime = prime; } public int compareTo(Node x){ return this.val>x.val ? 1:-1; } } }
LeetCode(313):Super Ugly Number
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原文地址：http://www.cnblogs.com/Lewisr/p/5248265.html
