Given N lines are in the form a*x + b*y = c (a>0 or a==0 & b>0). Find the number of pairs of lines intersecting at a point.
x + 2y = 2
x + 2y = 4
- Parallel lines never intersect so a method is needed to exclude parallel lines for each line.
- The slope of a line can be represented as pair(a, b). Construct a map with key as slope and value as a set with c as entries in it so that it has an account of the parallel lines.
- Iterate over the lines add them to the map and maintain a variable Tot which counts the total number of lines till now.
- Now for each line update the Tot variable then add Tot to the answer and subtract the number of parallel lines to that line including itself.
Below is the implementation of the above approach:
Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.
- Number of pairs of lines having integer intersection points
- Program for Point of Intersection of Two Lines
- Maximum distinct lines passing through a single point
- Find intersection point of lines inside a section
- Count ways to divide circle using N non-intersecting chord | Set-2
- Count ways to divide circle using N non-intersecting chords
- Count number of pairs (A <= N, B <= N) such that gcd (A , B) is B
- Count number of pairs (i, j) such that arr[i] * arr[j] = arr[i] + arr[j]
- Count pairs (A, B) such that A has X and B has Y number of set bits and A+B = C
- Given two arrays count all pairs whose sum is an odd number
- Count pairs with sum as a prime number and less than n
- Count pairs with Bitwise AND as ODD number
- Count number of pairs with positive sum in an array
- Count all pairs of divisors of a number N whose sum is coprime with N
- Count number of ordered pairs with Even and Odd Product
- Count number of pairs in array having sum divisible by K | SET 2
- Count number of ordered pairs with Even and Odd Sums
- Count pairs of natural numbers with GCD equal to given number
- Queries to count the number of unordered co-prime pairs from 1 to N
- Count of pairs in a given range with sum of their product and sum equal to their concatenated number
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to firstname.lastname@example.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.