摘要： 约束的个数。代码：#include<iostream>#include<fstream>using namespace std;int n,m;long long ans;int a[432][432];int b[432];void read(){// ifstream cin("in.txt"); int i,j,k; for(i=2;i<=431;i+=2) a[i][2]=a[i/2][2]+1; for(i=3;i<=431;i+=2) if(b[i]==0) { a[i][i]=1; for(j=2*i;j<=431;j 阅读全文

摘要： 递推欧拉函数。代码：#include<iostream>#include<fstream>#include<cmath>using namespace std;int b[1001];int n;void read(){// ifstream cin("in.txt"); int i,j,k,ans; for(i=2;i<=1000;i++) b[i]=i; for(i=2;i<=1000;i+=2) b[i]/=2; for(i=3;i<=1000;i+=2) if(b[i]==i) for(j=i;j<=100 阅读全文

摘要： 原来欧拉函数也存在递推关系。代码：#include<iostream>#include<fstream>#include<cmath>using namespace std;long long b[1000001];int n;void read(){// ifstream cin("in.txt"); int i,j,k,ans; for(i=2;i<=1000000;i++) b[i]=i; for(i=2;i<=1000000;i+=2) b[i]/=2; for(i=3;i<=1000000;i+=2) if(b 阅读全文

摘要： 欧拉函数。代码：#include<iostream>#include<fstream>#include<cmath>using namespace std;int a[1001];int b[1000001];int n,m;void read(){// ifstream cin("in.txt"); int i,j,k,ans,s; for(i=4;i<=1000;i+=2) a[i]=1; for(i=3;i<=1000;i+=2) if(a[i]==0) for(j=2*i;j<=1000;j+=i) a[j]=1 阅读全文

摘要： 欧拉函数。代码：#include<iostream>#include<fstream>#include<cmath>using namespace std;int a[40001];long long n,m;void read(){// ifstream cin("in.txt"); int i,j,k; long long ans; for(i=4;i<=40000;i+=2) a[i]=1; for(i=3;i<=40000;i+=2) if(a[i]==0) { for(j=2*i;j<=40000;j+=i) 阅读全文