刚开始我想着用BFS做的......

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define abs_(x) max(x,-(x))
ll s,t,l,r;
int get(ll nl,ll nr)
{
    if(nl<=t&&nr>=t) return 0;
    ll tl=min(min(2*l-nl,2*l-nr),min(2*r-nl,2*r-nr));
    ll tr=max(max(2*l-nl,2*l-nr),max(2*r-nl,2*r-nr));
    return get(tl,tr)+1;
}
int work()
{
    scanf("%lld %lld %lld %lld",&s,&t,&l,&r);
    if(s%2!=t%2) return -1;
    if(l==r)
    {
        if(abs_(s-l)!=abs_(t-l)) return -1;
        if(s==t) return 0;
        return 1;
    }
    return get(s,s);
}
signed main()
{
    int T;
    scanf("%d",&T);
    while(T--) printf("%d\n",work());
    return 0;
}