POJ2739 Sum of Consecutive Prime Numbers【素数筛选+尺取法】

Sum of Consecutive Prime Numbers
Time Limit: 1000MS   Memory Limit: 65536K
Total Submissions: 25286   Accepted: 13793

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

Source

Japan 2005


Regionals 2005 >> Asia - Tokyo


问题链接:UVALive3399 UVA1210 POJ2739 Sum of Consecutive Prime Numbers。

#include 
#include 
#include 
#include 
#include 
using namespace std;

const int N=10001;       //之所以大一是因为后面爱氏筛选法里面素数条件有关,所以要多一个素数,而10001恰好就是素数。
int primes[N+1];
const int SQRT=ceil(sqrt((double)N));

void esieve()
{
    memset(primes,1,sizeof(primes));
    primes[0]=primes[1]=0;
    for(int i=0;i<=SQRT;i++)
    {
        if(primes[i])
        {
            for(int j=i*i;j

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