日后学习。。。。。

AC（博主的纯数学做法）

/*
皮卡丘冲鸭！
へ　　　　　／|
　　/＼7　　　 ∠＿/
　 /　│　　 ／　／
　│　Z ＿,＜　／　　 /`ヽ
　│　　　　　ヽ　　 /　　〉
　 Y　　　　　`　 /　　/
　ｲ●　､　●　　⊂⊃〈　　/
　()　 へ　　　　|　＼〈
　　>ｰ ､_　 ィ　 │ ／／
　 / へ　　 /　ﾉ＜| ＼＼
　 ヽ_ﾉ　　(_／　 │／／
　　7　　　　　　　|／
　　＞―r￣￣`ｰ―＿
*/
#include <iostream>
#include <bits/stdc++.h>
#define For(i,x,y) for(int i=(x); i<=(y); i++)
#define fori(i,x,y) for(int i=(x); i<(y); i++)
#define rep(i,y,x) for(int i=(y); i>=(x); i--)
#define mst(x,a) memset(x,a,sizeof(x))
#define pb push_back
#define sz(a) (int)a.size()
#define mp make_pair
#define fi first
#define se second
#define debug(a) cout << #a << ": " << a << endl
using namespace std;
typedef long long ll;
typedef pair<int,int>pa;
typedef pair<ll,ll>pai;
const int N = 2e5+10;
const int M = 1e4;
ll h,c,t;
struct Type{
    
    
    ll t1, t2;
    ll res;
    bool operator<(const Type x)const{
    
    
        if(abs(t1*x.t2 - t*t2*x.t2) != abs(x.t1*t2-t*x.t2*t2))
            return abs(t1*x.t2 - t*t2*x.t2) < abs(x.t1*t2-t*x.t2*t2);
        else return res<x.res;
    }
};
int main()
{
    
    
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int tt;
    cin>>tt;
    while(tt--){
    
    
        cin>>h>>c>>t;
        if(h<=t)cout<<1<<endl;
        else if(h+c>=t*2)cout<<2<<endl;
        else {
    
    
            ll ss = t-c;
            ll s = 2*t-c-h;
            ll res = ss/s;
            ll ans = res*2-1;
            vector<Type> v;
            ll t1 ;//= (res-1)*(h+c)-c;
            ll t2;
            if(res){
    
    
                t1 = (res-1)*(h+c)-c;
                t2 = 2*(res-1)-1;
                v.pb({
    
    t1,t2,res-1});
               // ll temp2 = (res-1)*2-1;
                //ll temp1 = res*2-1;
                //if(abs(t1*temp2 - t*temp2*temp1) > abs(t2*temp1-t*temp1*temp2))ans=(res-1)*2-1;
               // ll t3 = (res+1)*(h+c)-c;
               // temp3 = (res+1)*2-1;
               // if(abs(t1*temp2 - t*temp2*temp1) < abs(t2*temp1-t*temp1*temp2))ans=(res+1)*2-1;
            }
            t1 = (res)*(h+c)-c;
            t2 = 2*(res)-1;
            v.pb({
    
    t1,t2,res});
            t1 = (res+1)*(h+c)-c;
            t2 = 2*(res+1)-1;
            v.pb({
    
    t1,t2,res+1});
            sort(v.begin(),v.end());
            cout<<(v[0].res*2-1)<<endl;
        }
    }
    return 0;
}

AC(某位红名大佬的二分)

//~ while (clock()<=69*CLOCKS_PER_SEC)
//~ #pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("O3")
//~ #pragma GCC target ("avx2")
//~ #pragma GCC optimize("Ofast")
//~ #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
//~ #pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace __gnu_pbds;
using namespace std;

template <typename T>
using ordered_set =
    tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

#define sim template < class c
#define ris return * this
#define dor > debug & operator <<
#define eni(x) sim > typename \
  enable_if<sizeof dud<c>(0) x 1, debug&>::type operator<<(c i) {
    
    
sim > struct rge {
    
     c b, e; };
sim > rge<c> range(c i, c j) {
    
     return rge<c>{
    
    i, j}; }
sim > auto dud(c* x) -> decltype(cerr << *x, 0);
sim > char dud(...);
struct debug {
    
    
#ifdef LOCAL
~debug() {
    
     cerr << endl; }
eni(!=) cerr << boolalpha << i; ris; }
eni(==) ris << range(begin(i), end(i)); }
sim, class b dor(pair < b, c > d) {
    
    
  ris << "(" << d.first << ", " << d.second << ")";
}
sim dor(rge<c> d) {
    
    
  *this << "[";
  for (auto it = d.b; it != d.e; ++it)
    *this << ", " + 2 * (it == d.b) << *it;
  ris << "]";
}
#else
sim dor(const c&) {
    
     ris; }
#endif
};
#define imie(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "

#define shandom_ruffle random_shuffle

using ll=long long;
using pii=pair<int,int>;
using pll=pair<ll,ll>;
using vi=vector<int>;
using vll=vector<ll>;
const int nax=1000*1007;

ll gor, zim, chce;

pll ula(ll v)
{
    
    
	ll mi=2*v+1;
	ll li=v*(gor+zim)+gor;
	return {
    
    li, mi};
}

void test()
{
    
    
	scanf("%lld%lld%lld", &gor, &zim, &chce);
	gor<<=1;
	zim<<=1;
	chce<<=1;
	if (chce<=(gor+zim)/2)
	{
    
    
		printf("2\n");
		return;
	}
	ll bsa=0;
	ll bsb=1e6;
	while(bsa<bsb)
	{
    
    
		ll bss=(bsa+bsb+2)>>1;
		pll wez=ula(bss);
		if (wez.first>=chce*wez.second)
			bsa=bss;
		else
			bsb=bss-1;
	}
	ll lew=bsa;
	ll pra=bsa+1;
	pll wl=ula(lew);
	pll wp=ula(pra);
	pll sr={
    
    wl.first*wp.second+wp.first*wl.second, wl.second*wp.second*2};
	if (sr.first<=chce*sr.second)
		printf("%lld\n", 2*lew+1);
	else
		printf("%lld\n", 2*pra+1);
}

int main()
{
    
    
	int t;
	scanf("%d", &t);
	while(t--)
		test();
	return 0;
}