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Re:过了贴代码攒rp,有注释有真相In Reply To:过了贴代码攒rp,有注释有真相 Posted by:1000010314 at 2012-01-21 14:11:38 > #include <iostream>
> #include <cstdlib>
> #include <cstdio>
> #include <cstring>
> #define max 10001
> #define sum 1230//10000以下总共有1229个素数
> using namespace std;
> int prime [sum];//这个数组用于存放素数
>
> int num(int n)//用于计算可能的组合的个数。
> {
> int a=prime[1],ans=0;//ans为个数,a为当前计算的和,n为目标值
> for(int i=1,j=2;j<sum&&prime[i]<=n&&i<=j;i++)
> {
> a-=prime[i-1];
> while(a<n&&j<sum)
> {
> a+=prime[j++];
> }
> if(a==n){ans++;}
> }
> return ans;
> }
>
>
> int main()
> {
> bool * data=new bool [max];//双下标法找素数
> memset(data,true,max*sizeof(bool));
> data[0]=false;data[1]=false;prime[0]=0;
> for(int i=2,j=1,k;i<max;i++)
> {
> if(!data[i]){continue;}
> prime[j++]=i;//记录素数
> for(k=(i<<1);k<max;k+=i){data[k]=false;}
> }
> delete(data);//不用了就释放内存
> int n;
> while(cin>>n)
> {
> if(!n){break;}
> cout<<num(n)<<endl;
> }
> return 0;
> }
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