Almost Prime Numbers UVA - 10539

 

 

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#include <iostream> #include <cstring> #include <cmath> #include <algorithm> using namespace std ;    const int M =1e6+33;  #define int long long  int b[M],c[M],tot;  int s[M] ;     void init(int top){      memset(b,1,sizeof b); b[1]=0;      int i,j;      for(i=2;i<=top;i++){          if(b[i]) c[++tot]=i;                    for(j=1;j<=tot&&i*c[j]<=top;j++){              b[i*c[j]]=0;              if(i%c[j]==0) break;         }      }  }     signed main(){     init(1e6);     int x,y,tes ;     cin>>tes;     while(tes--){         int ans =0;         cin>>x>>y;                   for(int i=1;i<=tot;i++)             for(int j=c[i]*c[i];j<=y;j*=c[i])                 if(j>=x) ans++;         cout<<ans<<'\n';     }  }