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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; > } Followed by: Post your reply here: |
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