BZOJ1876: [SDOI2009]SuperGCD

  1 #include<iostream>
  2 #include<algorithm>
  3 #include<cstdio>
  4 #include<cstring>
  5 #include<cmath>
  6 #include<cstdlib>
  7 #include<vector>
  8 using namespace std;
  9 typedef long long ll;
 10 typedef long double ld;
 11 typedef pair<int,int> pr;
 12 const double pi=acos(-1);
 13 #define rep(i,a,n) for(int i=a;i<=n;i++)
 14 #define per(i,n,a) for(int i=n;i>=a;i--)
 15 #define Rep(i,u) for(int i=head[u];i;i=Next[i])
 16 #define clr(a) memset(a,0,sizeof(a))
 17 #define pb push_back
 18 #define mp make_pair
 19 #define fi first
 20 #define sc second
 21 #define pq priority_queue
 22 #define pqb priority_queue <int, vector<int>, less<int> >
 23 #define pqs priority_queue <int, vector<int>, greater<int> >
 24 #define vec vector
 25 ld eps=1e-9;
 26 ll pp=1000000007;
 27 ll mo(ll a,ll pp){if(a>=0 && a<pp)return a;a%=pp;if(a<0)a+=pp;return a;}
 28 ll powmod(ll a,ll b,ll pp){ll ans=1;for(;b;b>>=1,a=mo(a*a,pp))if(b&1)ans=mo(ans*a,pp);return ans;}
 29 //void fre() { freopen("c://test//input.in", "r", stdin); freopen("c://test//output.out", "w", stdout); }
 30 //void add(int x,int y,int z){ v[++e]=y; next[e]=head[x]; head[x]=e; cost[e]=z; }
 31 int dx[5]={0,-1,1,0,0},dy[5]={0,0,0,-1,1};
 32 ll read(){ ll ans=0; char last=‘ ‘,ch=getchar();
 33 while(ch<‘0‘ || ch>‘9‘)last=ch,ch=getchar();
 34 while(ch>=‘0‘ && ch<=‘9‘)ans=ans*10+ch-‘0‘,ch=getchar();
 35 if(last==‘-‘)ans=-ans; return ans;
 36 }
 37 #define P 1000000000
 38 #define N 10005
 39 char ch[N];
 40 struct Hp{
 41     int len,nu[N/9+5];
 42     Hp(){
 43         len=0; memset(nu,0,sizeof(nu));
 44     }
 45     void read(){
 46         scanf("%s",ch); int slen=strlen(ch);
 47         if (slen%9==0) len=slen/9;
 48         else len=slen/9+1;
 49         for (int i=1;i<=len;i++){
 50             int g=1;
 51             for (int j=0;j<9;j++)
 52                 if (slen-1-(i-1)*9-j>=0) {
 53                 nu[i]+=(ch[slen-1-(i-1)*9-j]-‘0‘)*g;
 54                 g*=10; 
 55             }
 56         }
 57     }
 58     void div2(){
 59         for (int i=len;i>0;i--) {
 60             if (nu[i]&1) nu[i-1]+=P;
 61             nu[i]>>=1;
 62         }
 63         if (nu[len]==0) len--;
 64     }
 65     void mul2(){
 66         for (int i=1;i<=len;i++) nu[i]<<=1;
 67         for (int i=1;i<=len;i++) 
 68             if (nu[i]>=P) nu[i]-=P,nu[i+1]++;
 69         if (nu[len+1]>0) len++;
 70     }
 71     friend bool operator >(Hp a,Hp b){
 72         if (b.len>a.len) return 0;
 73         if (b.len<a.len) return 1;
 74         for (int i=a.len;i>0;i--){
 75             if (a.nu[i]>b.nu[i]) return 1;
 76             if (a.nu[i]<b.nu[i]) return 0;
 77         }
 78         return 1;
 79     }
 80     friend Hp operator -(Hp a,Hp b){
 81         Hp c; c.len=a.len;
 82         for (int i=a.len;i>0;i--)
 83             c.nu[i]=a.nu[i]-b.nu[i];
 84         for (int i=1;i<=c.len;i++)
 85           if (c.nu[i]<0) c.nu[i+1]--,c.nu[i]+=P;
 86         while (c.nu[c.len]==0&&c.len) c.len--;
 87         return c; 
 88     }
 89     bool z(){
 90         for (int i=len;i>0;i--)
 91             if (nu[i]>0) return 0;
 92         return 1;
 93     }
 94     void out(){
 95         for (int i=len;i>0;i--) 
 96             if (i==len) printf("%d",nu[i]);
 97             else printf("%09d",nu[i]);
 98     }
 99 };
100 int main()
101 {
102     Hp a,b; a.read(); b.read(); int num=0;
103     while(1)
104     {
105         if((a.nu[1]%2==0)&&(b.nu[1]%2==0)){a.div2();b.div2();num++;}
106         else if((a.nu[1]%2==0)) a.div2();
107         else if((b.nu[1]%2==0)) b.div2();
108         if(a>b){a=a-b; if(a.z()){while(num--)b.mul2();b.out();break;}}
109         else {b=b-a; if(b.z()){while(num--)a.mul2();a.out();break;}}
110     }
111     return 0;
112  }