Graham Scan - Time Complexity

Time Complexity

Sorting the points has time complexity O(n log n). While it may seem that the time complexity of the loop is O(n2), because for each point it goes back to check if any of the previous points make a "right turn", it is actually O(n), because each point is considered at most twice in some sense. Each point can appear only once as a point in a "left turn" (because the algorithm advances to the next point after that), and as a point in a "right turn" (because the point is removed). The overall time complexity is therefore O(n log n), since the time to sort dominates the time to actually compute the convex hull.

Read more about this topic:  Graham Scan

Famous quotes containing the words time and/or complexity:

    “The writer who aims at producing the platitudes which are “not for an age, but for all time” has his reward in being unreadable in all ages.... The man who writes about himself and his own time is the only sort of man who writes about all people and about all time.”
    —George Bernard Shaw (1856–1950)

    “The price we pay for the complexity of life is too high. When you think of all the effort you have to put in—telephonic, technological and relational—to alter even the slightest bit of behaviour in this strange world we call social life, you are left pining for the straightforwardness of primitive peoples and their physical work.”
    —Jean Baudrillard (b. 1929)