A：签到。
#include<iostream> #include<cstdio> #include<cmath> #include<cstdlib> #include<cstring> #include<algorithm> using namespace std; #define ll long long char getc(){char c=getchar();while ((c<'A'||c>'Z')&&(c<'a'||c>'z')&&(c<'0'||c>'9')) c=getchar();return c;} int gcd(int n,int m){return m==0?n:gcd(m,n%m);} int read() { int x=0,f=1;char c=getchar(); while (c<'0'||c>'9') {if (c=='-') f=-1;c=getchar();} while (c>='0'&&c<='9') x=(x<<1)+(x<<3)+(c^48),c=getchar(); return x*f; } int T; int main() { /*#ifndef ONLINE_JUDGE freopen("a.in","r",stdin); freopen("a.out","w",stdout); #endif*/ T=read(); while (T--) { int n=read(),x=read(),y=read(),d=read(); if (abs(y-x)%d==0) cout<<abs(y-x)/d<<endl; else { int ans=2000000000; if ((y-1)%d==0) ans=min(ans,(y-1)/d+(x-2)/d+1); if ((n-y)%d==0) ans=min(ans,(n-y)/d+(n-x-1)/d+1); if (ans==2000000000) cout<<-1<<endl; else cout<<ans<<endl; } } return 0; }