Example Gallery

Find Pair Sum In Sorted MArray

The code snippet below uses the famous two pointer technique to find the pair sum 17 in the sorted array [2, 3, 5, 8, 9, 10, 11].

Example: PairSumExample

from manim import *

from manim_data_structures import *

class PairSumExample(Scene):
    def isPairSumAnim(self, arr, n, val):
        p_i = MArrayPointer(self, arr, 0, 'i', mob_arrow_args={'color': GREEN}, mob_label_args={'color': GREEN})
        p_j = MArrayPointer(self, arr, n - 1, 'j', mob_arrow_args={'color': YELLOW}, mob_label_args={'color': YELLOW})
        pair_sum = MVariable(self, 0, label='Sum')
        pair_sum.shift(DOWN * 2)

        self.play(Create(pair_sum))
        self.play(Create(p_i), Create(p_j))

        while (p_i.fetch_index() < p_j.fetch_index()):
            pair_sum.update_value(arr.fetch_arr()[p_i.fetch_index()] + arr.fetch_arr()[p_j.fetch_index()])

            if (pair_sum.fetch_value() == val):
                self.play(pair_sum.fetch_mob_square().animate.set(fill_color=GREEN))
                return True
            elif(pair_sum.fetch_value() < val):
                p_i.shift_to_elem(p_i.fetch_index() + 1)
            else:
                p_j.shift_to_elem(p_j.fetch_index() - 1)

        self.play(pair_sum.fetch_mob_square().aniamte.set(fill_color=RED))
        return False

    def construct(self):
        arr = MArray(self, [2, 3, 5, 8, 9, 10, 11], label='Array')
        arr.shift(UP + LEFT * 2)
        self.add(arr)
        self.isPairSumAnim(arr, 7, 17)
        self.wait(1)

Maxmimum Sum of K Consecutive Integers in MArray

The code snippet below uses the sliding window technique to find the maximum sum of k = 4 consecutive elements in the array [1, 4, 2, 10, 2, 3, 1, 0, 20]

Example: PairSumExample

from manim import *

from manim_data_structures import *

class PairSumExample(Scene):
    def maxSumAnim(self, marr: MArray, k):
        arr = marr.fetch_arr()
        n = len(arr)

        window = MArraySlidingWindow(self, marr, 0, k, 'Window')
        var_window_sum = MVariable(self, sum(arr[:k]), label='Window Sum')
        var_max_sum = MVariable(self, var_window_sum.fetch_value(), label='Max Sum')
        var_window_sum.shift(DOWN)
        var_max_sum.shift(DOWN * 2.5)

        self.play(Create(window))
        self.play(Create(var_window_sum), Create(var_max_sum))

        for i in range(n - k):
            window.shift_to_elem(i + 1)
            var_window_sum.update_value(var_window_sum.fetch_value() - arr[i] + arr[i + k])
            if var_window_sum.fetch_value() > var_max_sum.fetch_value():
                var_max_sum.update_value(var_window_sum.fetch_value())


        self.play(var_max_sum.fetch_mob_square().animate.set(fill_color=GREEN))
        return var_max_sum.fetch_value()

    def construct(self):
        arr = MArray(self, [1, 4, 2, 10, 2, 3, 1, 0, 20], label='Array')
        arr.shift(UP * 1.5 + LEFT * 4)
        self.add(arr)
        self.maxSumAnim(arr, 4)
        self.wait(1)