C++(clang++11) 解法, 执行用时: 28ms, 内存消耗: 544K, 提交时间: 2021-02-09 21:22:38

#include<iostream>
using namespace std;
#define rep(i,n) for(int i=1;i<=n;++i)
int gcd(int a,int b){return b==0?a:gcd(b,a%b);}
int main(){
	int t,a,b,c;cin>>t;
	while(t--){
		cin>>a>>b>>c;int n=b,d=1,f=0;
		rep(i,c){
			if(n*1.0/d<(a*i+b)*1.0/(1<<i))n=a*i+b,d=1<<i;
		}
		if(n%d){
			if(n<0)n=-n,f=1;
			int g=gcd(n,d);if(f)cout<<"-";
			cout<<n/g<<"/"<<d/g<<endl;
		}
		else cout<<n/d<<endl;
	}
	return 0;
}

Python3(3.9) 解法, 执行用时: 625ms, 内存消耗: 4004K, 提交时间: 2020-12-26 17:00:20

from fractions import Fraction
t = int(input())
for _ in range(t):
    a, b, n = map(int, input().split())
    m = Fraction(b, 1)
    for x in range(n + 1):
        m = max(m, Fraction(a * x + b, 2**x))
    print(m)