- #include
- #include
- #include
- #include
- #include
- <
- string
- >
- #include
- using namespace std;
- #define
- _ ios::sync_with_stdio(false),cin.tie(0)
- const int
- MAXN =
- 5010;
- const int
- INF =
- 0xfffffff;
- typedef long long ll;
- int t;
- ll x,y,p,q;
- int main()
- {
- cin
- >>
- t;
- while
- (t--
- )
- {
- cin
- >>x>>y>>p>>
- q;
- ll l
- =
- 0
- ,r=1e9,ans=-
- 1;
- while
- (l<=
- r)
- {
- ll mid
- =(l+r)>>
- 1;
- ll a
- =mid*p-x,b=mid*q-
- y;
- if
- (a>=
- 0
- &&b>=
- 0
- &&a<=
- b)
- {
- ans
- =
- mid;
- r
- =mid-
- 1;
- }
- else
- l
- =mid+
- 1;
- }
- if
- (ans==-
- 1)
- cout
- <<-
- 1
- <<
- endl;
- else
- cout
- <
- endl;
- }
- return 0;
- }
来源: http://www.bubuko.com/infodetail-2155844.html