hdu 3641 2010 Asia Regional Hangzhou Site —— Online Contest 数论题，分解质因子

先记录所有数相乘的质因子，再二分一个x判断x！是否能被M整除

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  1 #include<stdio.h>
  2 #include<string.h>
  3 #include<math.h>
  4 #define  lld __int64
  5 lld num[110];
  6 lld a[110],b[110];
  7 void cal(lld n,lld count)
  8 {
  9     int i,cnt;
 10     for(i=2;i*i<=n;i++)
 11     {
 12         cnt=0;
 13         if(n%i==0)
 14         {
 15             n/=i;
 16             cnt++;
 17             while(n%i==0)
 18             {
 19                 n/=i;
 20                 cnt++;
 21             }
 22             num[i]+=cnt*count;
 23         }
 24         if(n==1) break;
 25     }
 26     if(n>1) num[n]+=count;
 27 }
 28 lld solve(lld n,lld x)
 29 {
 30     lld ans=0;
 31     while(n)
 32     {
 33         n/=x;
 34         ans+=n;
 35     }
 36     return ans;
 37 }
 38 bool judge(lld x)
 39 {
 40     lld i,temp;
 41     for(i=1;i<=100;i++)
 42     {
 43         if(num[i])
 44         {
 45              temp=solve(x,i);
 46              if(num[i]>temp) 
 47                  return false;
 48         }
 49     }
 50     return true;
 51 }
 52 int main()
 53 {
 54     int t,n,i;
 55     lld ans;
 56     scanf("%d",&t);
 57     while(t--)
 58     {
 59         scanf("%d",&n);
 60         memset(num,0,sizeof(num));
 61         for(i=0;i<n;i++)
 62         {
 63             scanf("%I64d%I64d",&a[i],&b[i]);
 64             cal(a[i],b[i]);
 65         }
 66         lld left=0,right=(lld(1)<<62);
 67         while(left<=right)
 68         {
 69             lld mid=(left+right)>>1;
 70             if(judge(mid))
 71             {
 72                 right=mid-1;
 73                 ans=mid;
 74             }
 75             else left=mid+1;
 76         }
 77         printf("%I64d\n",ans);
 78     }
 79     return 0;
 80 }
 81     int t,n,i;
 82     lld ans;
 83     scanf("%d",&t);
 84     while(t--)
 85     {
 86         scanf("%d",&n);
 87         memset(num,0,sizeof(num));
 88         for(i=0;i<n;i++)
 89         {
 90             scanf("%I64d%I64d",&a[i],&b[i]);
 91             cal(a[i],b[i]);
 92         }
 93         lld left=0,right=(lld(1)<<62);
 94         while(left<=right)
 95         {
 96             lld mid=(left+right)>>1;
 97             if(judge(mid))
 98             {
 99                 right=mid-1;
100                 ans=mid;
101             }
102             else left=mid+1;
103         }
104         printf("%I64d\n",ans);
105     }
106     return 0;
107 }