UVA 1213 - Sum of Different Primes(递推) 类似一个背包问题的计数问题。(虽然我也不记得这叫什么背包了 一开始我想的状态定义是:f[n = 和为n][k 个素数]。 递推式呼之欲出: f[n][k] = sigma f[n-pi][k-1]。 但是题目还有一个要求是不同素数之和,为了保证素数不同,那就先枚举素数吧, f[i...
Uva 1213 - Sum of Different Primes(DP) 题目链接 https://vjudge.net/problem/UVA-1213 【题意】 给定两个正整数n, k (n<=1120,k<=14), 求用k个互不相同的素数凑出和为n的方案总数 【思路】 先要用埃氏筛选打出[0,1120]内的素数表,下一步就是动态规划了,这个问题类似于01背包问题,设dp(k,i...
#include<bits/stdc++.h> usingnamespacestd; typedeflonglongll; constintmaxn=1120; boolcheck[maxn]; intprime[1120]; lldp[1122][15]; intinit(intn){ memset(check,0,sizeof(check)); inttot=0; check[0]=check[1]=1; for(inti=2;i<=n;i++){ if(!check[i])prime[tot++]=i; for(i...
A positive integer may be expressed as a sum of different prime numbers (primes), in one way or another. Given two positive integersnandk, you should count the number of ways to expressnas a sum ofkdifferent primes. Here, two ways are considered to be the same if they sum up the sam...
UVa01213_SumofDifferentPrimes.java UVa01225_DigitCounting.java UVa01226_Numericalsurprises.java UVa01230_MODEX.java UVa01235_AntiBruteForceLock.java UVa01237_ExpertEnough.java UVa01251_RepeatedSubstitutionwithSed.java UVa01260_Sales.java UVa01261_StringPopping.java UVa01262_Password.java UVa10000_LongestPat...
Squares of primesPowers of 2Linnik’s almost Goldbach problemIn this paper, it is proved by a different method that every sufficiently large odd integer can be written as a sum of one prime, two squares of primes and 17 powers of 2, which improves the previous...
There are only 1+5 or 0+6 can get a 6, but both b,c are prime numbers, so its has to be 1+5, and the units digit is a prime number of 5 only has to be 5. So, assuming that b=5, then c2=5066−25=5041, so c=71. Above all, the product of these three primes is ...
On sum of one prime, two squares of primes and powers of 2 In this paper, it is proved by a different method Lu,Guangshi - 《Monatshefte Fur Mathematik》 被引量: 2发表: 2018年 ON PAIRS OF ONE PRIME, TWO PRIME SQUARES AND POWERS OF 2 In this short paper, it is proved that every...
We will give two different proofs of this result, one based on a theorem of Evertse (yielding, for a fixed finite set of primes S , an effective bound on the number of non-degenerate solutions of an S -unit equation in k variables over the rationals) and the other using only ...
Assuming that p, q, and r are distinct primes, how many positive divisors does m have? 1) If m = q^3 2) If m= p^(2)q^(2) 3) If m = pqr How many prime numbers are there between 25 and 35, inclusive? How many different positive integers divisible by 4 c...