In many programming competitions, we are asked to find (or count the number of) Prime Factors of an integer i. This is boring. This time, let’s count the number of Non-Prime Factors of an integer i, denoted as NPF(i). For example, integer 100 has the…

题目链接 http://www.patest.cn/contests/pat-a-practise/1059 Given any positive integer N, you are supposed to find all of its prime factors, and write them in the format N = p1^k1 * p2^k2 *…*pm^km. Input Specification: Each input file contains one test ca…

题目大意 求区间[L, R]中距离最大和最小的两对相邻质数.R<2^31, R-L<1e6. 总体思路 本题数据很大.求sqrt(R)的所有质数,用这些质数乘以j, j+1, j+2...k(j和k使得积属于[L,R])筛选出[L,R]中的合数,然后在[L,R]的质数中得到所求. 筛法求质数 为在O(n)的时间复杂度中求得质数,我们要使筛选时每个可能为质数的数只访问一次.我们用v[i]表示i的最小质因数.每次循环到i时,假设v[i]和小于i的质数都已经在前面求出来了,若v[i]==0,则i是个…

7.7 Design an algorithm to find the kth number such that the only prime factors are 3,5, and 7. 这道题跟之前LeetCode的那道Ugly Number II 丑陋数之二基本没有啥区别,具体讲解可参见那篇,代码如下: class Solution { public: int getKthMagicNumber(int k) { vector<, ); , i5 = , i7 = ; while (re…

Prime Distance Time Limit: 2 Seconds      Memory Limit: 65536 KB The branch of mathematics called number theory is about properties of numbers. One of the areas that has captured the interest of number theoreticians for thousands of years is the ques…

题目大意 给定两个数L和U,要求你求出在区间[L, U] 内所有素数中,相邻两个素数差值最小的两个素数C1和C2以及相邻两个素数差值最大的两个素数D1和D2,并且L-U<1,000,000 题解 由于1<=L< U<=2,147,483,647,直接筛肯定超时,但是题目说L-U<1,000,000,我们可以先筛选出sqrt(2147483647)(约等于46340)内的素数即可,然后再用这些素数把区间[L,U]内的合数筛选掉,最后就可以枚举答案了~~~ 代码: #includ…

问题 L: Prime Factors 时间限制: 1 Sec  内存限制: 128 MB [提交][状态][论坛] 题目描写叙述 I'll give you a number , please tell me how many different prime factors in this number. 输入 There is multiple test cases , in each test case there is only one line contains a number N(…

1059 Prime Factors (25 分)   Given any positive integer N, you are supposed to find all of its prime factors, and write them in the format N = p​1​​​k​1​​​​×p​2​​​k​2​​​​×⋯×p​m​​​k​m​​​​. Input Specification: Each input file contains one test case whi…

题目 Given any positive integer N, you are supposed to find all of its prime factors, and write them in the format N = p1^k1 * p2^k2 -pm^km. Input Specification: Each input file contains one test case which gives a positive integer N in the range of lo…

1059. Prime Factors Given any positive integer N, you are supposed to find all of its prime factors, and write them in the format N = p1^k1 * p2^k2 *-*pm^km. Input Specification: Each input file contains one test case which gives a positive integer N…