标签:排序 void who sof end pre space cond int
传送门:QWQ
先考虑两个人
a0 | b0 | |
---|---|---|
p1 | a1 | b1 |
p2 | a2 | b2 |
那么满足:\(\huge ans1=\max(\frac{a0}{b1} , \frac{a0a1}{b2})\)
a0 | b0 | |
---|---|---|
p2 | a2 | b2 |
p2 | a1 | b1 |
\(\huge ans2=\max(\frac{a0}{b2} , \frac{a0a2}{b1})\)
如果要让ans1<ans2
设 \(k1=\frac{a0}{b1} , k2=\frac{a0a1}{b2} , k3=\frac{a0}{b2} , k4=\frac{a0a2}{b1}\)
则 k1< k4
k2 > k3
如果要让ans1
展开,得:\(\frac{a0a2}{b1} > \frac{a0a1}{b2}\)
移项得:\(a1b1<a2b2\)
根据冒泡排序
两个相邻交换一定使答案更差
所以可以根据ab的大小排序(下标排序)
然后就是麻烦的高精了
//自动无视c++14
// luogu-judger-enable-o2
#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
const int maxn=1e4+5;
int n;
// The MIT License (MIT)
// Copyright (c) YEAR NAME
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
struct big{
static const int base=10000;
int a[2333];
int len;
big(){memset(a,'\000',sizeof a);len=1;}
int& operator[](int x){return a[x];}
big(int x){*this=x;}
big& operator =(int x){
*this=big();
for(len=0;x;x/=base)a[++len]=x%base;
if(!x)len=1;
return *this;
}
friend big operator + (const big&a,const big& b){
big c;
c.len=max(a.len,b.len);
for(int i=1;i<=c.len;++i){
c[i+1]+=((c[i]+=(a.a[i]+b.a[i]))/base);
c[i]%=base;
}
if(c[c.len+1])c.len++;
return c;
}
friend big operator * (const big&a,const big& b){
big c;
c.len=a.len+b.len-1;
for(int i=1;i<=a.len;++i){
for(int j=1;j<=b.len;++j){
c[i+j-1]+=a.a[i]*b.a[j];
c[i+j]+=c[i+j-1]/base;
c[i+j-1]%=base;
}
}
while(c[c.len+1]){
c[c.len+1]+=c[c.len]/base;
c[c.len]%=base;
c.len++;
}
return c;
}
friend big operator + (const big a,int b){big c(b);return a+c;}
friend big operator * (const big a,int b){big c(b);return a*c;}
friend bool operator < (const big & a,const big&b){
if(a.len==b.len){
for(int i=a.len;i;--i){
if(a.a[i]!=b.a[i])return a.a[i]<b.a[i];
}
}else{
return a.len<b.len;
}
return 0;
}
friend big operator / (const big& a,int x){
big ans;
ans.len=a.len;
int jw=0;
for(int i=ans.len;i;--i){
ans[i]=(jw*base+a.a[i])/x;
((jw*=base)+=a.a[i])%=x;
}
while(!ans[ans.len]&&ans.len)ans.len--;
return ans;
}
void print()const{printf("%d",a[len]);
for(int i=len-1;i;i--){
printf("%04d",a[i]);
}
}
friend ostream& operator << (ostream& out,const big& a){
a.print();
return out;
}
};
int a[maxn],b[maxn];
int bit[maxn];
big f[maxn];
big ans;
big mul(1);
int main(){
cin>>n;
for(int i=0;i<=n;++i){
cin>>a[i]>>b[i];
big x(a[i]),y(b[i]);
f[i]=x*y;
bit[i]=i;
}
sort(bit+1,bit+1+n,[](const int& a,const int& b){
return f[a]<f[b];
});
for(int i=0;i<=n;++i){
if(i)ans=max(ans,mul/b[bit[i]]);
mul=mul*a[bit[i]];
}
ans.print();
return 0;
}
标签:排序 void who sof end pre space cond int
原文地址:https://www.cnblogs.com/eric-walker/p/9535445.html