Recently I was upsolving this problem. My subtask was as follows: given three points: A, B, C
, and I need to find the intersection point of 2 lines: AB and OC, where O has (0;0) coordinates.
At first I wrote this using a formula (find()
function) and got WA on 2 tests. Then I wrote it using binary search (findgood()
function) and got AC. Then I submitted the solution above with find()
and #define ld __float128
, and it passed.
Can anybody explain what actually happened? How can formula be less precise than binary search?