bzoj1024题解

【解题思路】

　　爆搜，状态f(r,x,y)表示剩下r刀，边长为x和y，对于每个状态枚举切成两块后的长度比或宽度比。复杂度o((n/2)ⁿ)。

【参考代码】

 #include <algorithm>
 #include <cstdio>
 #define REP(I,start,end) for(int I=(start);I<=(end);I++)
 #define PER(I,start,end) for(int I=(start);I>=(end);I--)
 #define REPs(I,start,end,step) for(int I=(start);I<=(end);I+=(step))
 #define PERs(I,start,end,step) for(int I=(start);I>=(end);I-=(step))
 #define maxint 32767
 #define maxlongint 2147483647
 #define maxint64 9223372036854775807ll
 using namespace std;
 typedef unsigned short US;
 typedef unsigned long UL;
 typedef long long LL;
 typedef unsigned long long ULL;
 inline int getint()
 {
     char ch=getchar();
     while((ch<''||ch>'')&&ch!='-')
         ch=getchar();
     int result=;
     bool impositive=ch=='-';
     if(impositive)
         ch=getchar();
     while(ch>=''&&ch<='')
     {
         result=(result<<)+(result<<)+ch-'';
         ch=getchar();
     }
     return impositive?-result:result;
 }
 inline int putint(int n)
 {
     int result=;
     char* sav=new char[];
     bool impositive=n<;
     if(impositive)
     {
         putchar('-');
         n=-n;
     }
     sav[]=n%+'';
     while(n/=)
         sav[result++]=n%+'';
     PER(i,result-,)
         putchar(sav[i]);
     delete []sav;
     return result+impositive;
 }
 inline LL getLL()
 {
     char ch=getchar();
     while((ch<''||ch>'')&&ch!='-')
         ch=getchar();
     LL result=0ll;
     bool impositive=ch=='-';
     if(impositive)
         ch=getchar();
     while(ch>=''&&ch<='')
     {
         result=(result<<)+(result<<)+ch-'';
         ch=getchar();
     }
     return impositive?-result:result;
 }
 inline int putLL(LL n)
 {
     int result=;
     char* sav=new char[];
     bool impositive=n<;
     if(impositive)
     {
         putchar('-');
         n=-n;
     }
     sav[]=n%+'';
     while(n/=)
         sav[result++]=n%+'';
     PER(i,result-,)
         putchar(sav[i]);
     delete []sav;
     return result+impositive;
 }
 template<typename integer> inline int read_int(integer &n)
 {
     char ch=getchar();
     while((ch<''||ch>'')&&ch!='-')
         ch=getchar();
     int result=n=integer();
     bool impositive=ch=='-';
     if(impositive)
         ch=getchar();
     while(ch>=''&&ch<='')
     {
         n=(n<<)+(n<<)+integer(ch-'');
         result++;
         ch=getchar();
     }
     if(impositive)
     {
         n=-n;
         result++;
     }
     return result;
 }
 template<typename integer> inline int write_int(integer n)
 {
     int result=;
     char* sav=new char[];
     bool impositive=n<;
     if(impositive)
     {
         putchar('-');
         n=-n;
     }
     sav[]=n%+'';
     while(n/=)
         sav[result++]=n%+'';
     PER(i,result-,)
         putchar(sav[i]);
     delete []sav;
     return result+impositive;
 }
 template<typename T> inline bool getmin(T &target,T pattern)
 {
     bool can=pattern<target;
     if(can)
         target=pattern;
     return can;
 }
 template<typename T> inline bool getmax(T &target,T pattern)
 {
     bool can=pattern>target;
     if(can)
         target=pattern;
     return can;
 }
 //==========================================Header Template================================================
 #include <iomanip>
 #include <iostream>
 double DFS(int rest,double _x,double _y)
 {
     if(rest==)
         return _x>_y?_x/_y:_y/_x;
     double result=maxlongint;
     REP(i,,rest>>)
     {
         long double x0=_x/rest,y0=_y/rest,_r=rest-i;
         getmin(result,min(max(DFS(i,x0*i,_y),DFS(_r,x0*_r,_y)),max(DFS(i,_x,y0*i),DFS(_r,_x,y0*_r))));
     }
     return result;
 }
 int main()
 {
     int x=getint(),y=getint(),n=getint();
     cout<<setiosflags(ios::fixed)<<setprecision()<<DFS(n,x,y)<<endl;
     return ;
 }