hdu 5317 RGCDQ(预处理)

#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
using namespace std;
int s[1000100][8];
int t,n,m,num;
int vis[1000100],su[1000100];
void biao()
{
    int i,j,k;
    num=0;
    memset(vis,0,sizeof(vis));
    vis[0]=vis[1]=1;
    for(i=2;i<=1000100;i++){
        if(!vis[i]) su[num++]=i;
        if(!vis[i])
        for(j=i*2;j<=1000100;j+=i){
            vis[j]=1;
        }
    }
}
int cal(int x) {
    int ret =  0;
    for(int j=0; su[j]*su[j]<=x; j++) {
        if(x%su[j]==0) {
            ret++;
          while(x%su[j]==0){
            x/=su[j];
          }
          if(!vis[x]){
            ret++;
            break;
          }
        }
    }
    return ret;
}
void pre()
{
    int cnt,temp;
    memset(s,0,sizeof(s));
    s[2][1]=1;
    for(int i=1;i<=1000100;i++){
       s[i][1]=s[i-1][1];s[i][2]=s[i-1][2];
       s[i][3]=s[i-1][3];s[i][4]=s[i-1][4];
       s[i][5]=s[i-1][5];s[i][6]=s[i-1][6];
       s[i][7]=s[i-1][7];
       cnt=cal(i);
       if(!vis[i]) cnt=1;
       s[i][cnt]++;
    }
}
int main()
{
    int i,j,k,a,b;
    biao();
    pre();
    //printf("%d\n",vis[143]);
    //printf("%d\n",cal(2310));
    //printf("%d\n",num);
    while(scanf("%d",&n)!=EOF)
    {
        for(i=0;i<n;i++){
          scanf("%d%d",&a,&b);a--;
          if(s[b][7]-s[a][7]>=2){
             //   printf("%d %d\n",s[b][7],s[a][7]);
              printf("7\n");continue;
          }
          else if(s[b][6]-s[a][6]>=2){
             printf("6\n");continue;
          }
          else if(s[b][5]-s[a][5]>=2){
             printf("5\n");continue;
          }
          else if(s[b][4]-s[a][4]>=2){
             printf("4\n");continue;
          }
          else if(s[b][3]-s[a][3]>=2){
             printf("3\n");continue;
          }
          else if(s[b][2]-s[a][2]>=2){
             printf("2\n");continue;
          }
          else printf("1\n");
        }
    }
    return 0;
}