zoukankan      html  css  js  c++  java
  • POJ 2739 Sum of Consecutive Prime Numbers【素数打表】

    解题思路:给定一个数,判定它由几个连续的素数构成,输出这样的种数

    用的筛法素数打表

    Sum of Consecutive Prime Numbers
    Time Limit: 1000MS   Memory Limit: 65536K
    Total Submissions: 20020   Accepted: 10966

    Description

    Some positive integers can be represented by a sum of one or more consecutive prime numbers. How many such representations does a given positive integer have? For example, the integer 53 has two representations 5 + 7 + 11 + 13 + 17 and 53. The integer 41 has three representations 2+3+5+7+11+13, 11+13+17, and 41. The integer 3 has only one representation, which is 3. The integer 20 has no such representations. Note that summands must be consecutive prime numbers, so neither 7 + 13 nor 3 + 5 + 5 + 7 is a valid representation for the integer 20. Your mission is to write a program that reports the number of representations for the given positive integer.

    Input

    The input is a sequence of positive integers each in a separate line. The integers are between 2 and 10 000, inclusive. The end of the input is indicated by a zero.

    Output

    The output should be composed of lines each corresponding to an input line except the last zero. An output line includes the number of representations for the input integer as the sum of one or more consecutive prime numbers. No other characters should be inserted in the output.

    Sample Input

    2
    3
    17
    41
    20
    666
    12
    53
    0

    Sample Output

    1
    1
    2
    3
    0
    0
    1
    2
    #include<iostream>  
    #include<cstdio>  
    #include<cstring>  
    #include<algorithm>  
    using namespace std;
    int prime[10000],num[10005];
    int main()
    {
    	int i,j,k=0,tmp,n;
    	for(i=0;i<=10000;i++) num[i]=1;
    	num[0]=0;
    	num[1]=0;
    	for(i=2;i<=10000;i++)
    	{
    		if(num[i])
    		{
    			prime[k++]=i;
    			for(tmp=i*2;tmp<=10000;tmp+=i)
    			num[tmp]=0;
    		}
    	}
    	while(scanf("%d",&n)!=EOF&&n)
    	{
    		int ans=0,sum;
    		for(i=0;i<k;i++)
    		{
    			sum=0;
    			for(j=i;j<k&&sum<n;j++)
    			sum+=prime[j];
    			if(sum==n)
    			ans++;	
    		}
    		printf("%d
    ",ans);
    	}	
    }
    

      

  • 相关阅读:
    python编写爬虫脚本并实现APScheduler调度
    python实践设计模式(一)概述和工厂模式
    90、java ftp 读取文件
    91、mysql批量删除表
    92、kkfile打印当前页
    CSS3实践之路(四):文本特效
    CSS3实践之路(六):CSS3的过渡效果(transition)与动画(animation)
    CSS3实践之路(二):盒子模型(box Model)和边框(border)
    CSS3实践之路(三):颜色(Color)和背景(Backgroud)
    谈谈javascript中的定时器
  • 原文地址:https://www.cnblogs.com/wuyuewoniu/p/4262293.html
Copyright © 2011-2022 走看看