Problem
Given the prime number n, output the number of prime numbers
Noticen <= 100000
The prime number is defined as a natural number greater than 1, and there are no other factors except 1 and it itself.
Given n = 3, return 2.
explanation:
[2,3,5], 3 is the second prime number.
Given n = 11, return 5.
explanation:
[2,3,5,7,11], 11 is the fifth prime number.
public class Solution { /** * @param n: the number * @return: the rank of the number */ public int kthPrime(int n) { // write your code here int num = 0; for (int i = 1; i < n; i++) { boolean isPrime = true; for (int j = 1; j < i; j++) { if (j != 1 && i % j == 0) { isPrime = false; break; } } if (isPrime) { num++; } } return num; } }
文章版权归作者所有,未经允许请勿转载,若此文章存在违规行为,您可以联系管理员删除。
转载请注明本文地址:https://www.ucloud.cn/yun/68601.html
Problem Find the kth smallest number in at row and column sorted matrix. Example Given k = 4 and a matrix: [ [1 ,5 ,7], [3 ,7 ,8], [4 ,8 ,9], ] return 5 Challenge O(k log n), n is the maximal n...
Problem Given two numbers n and k. We need to find out if n can be written as sum of k prime numbers. Example Given n = 10, k = 2Return true // 10 = 5 + 5 Given n = 2, k = 2Return false Solution pub...
Problem Write a program to check whether a given number is an ugly number`. Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. For example, 6, 8 are ugly while 14 is not ugly ...
摘要:建两个新数组,一个存数,一个存。数组中所有元素初值都是。实现的过程是,一个循环里包含两个子循环。两个子循环的作用分别是,遍历数组与相乘找到最小乘积存入再遍历一次数组与的乘积,结果与相同的,就将加,即跳过这个结果相同结果只存一次。 Problem Write a program to find the nth super ugly number. Super ugly numbers a...
摘要:可以不要用太简单的方法。先把它装满,再和队列顶端的数字比较,大的就替换掉,小的就。遍历完所有元素之后,顶部的数就是第大的数。 Problem Find K-th largest element in an array. Example In array [9,3,2,4,8], the 3rd largest element is 4.In array [1,2,3,4,5], the...
阅读 3608·2021-11-16 11:41
阅读 2818·2021-09-23 11:45
阅读 644·2019-08-30 15:44
阅读 505·2019-08-30 13:10
阅读 1936·2019-08-30 12:49
阅读 3482·2019-08-28 17:51
阅读 1444·2019-08-26 12:20
阅读 672·2019-08-23 17:56