'''
    DS2000
    Fall 2024
    Starter code for lecture on 10/22/24

    Complete the code for the functions below (function signatures are
    in the code below, along with name/params/return type). The last one
    is optional and just for funsies. We should get through the first three
    all together!
'''

import random

def print_row_first(lst):
    '''
        Parameter: 2d list of any values
        Returns: nothing
        Does: Prints the element at position 0 within each list
    '''
    for row in lst:
        print(row[0])


def print_row_first_v2(lst):
    '''
        (Another version -- the morning/afternoon sections approached it differently
            but both work!)
        Parameter: 2d list of any values
        Returns: nothing
        Does: Prints the element at position 0 within each list
    '''
    for i in range(len(lst)):
        print(lst[i][0])

def multiply_2d(lst, val):
    '''
        parameters: 2d list of ints/floats, int/float to multiply by
        returns: 2d list
        does: computes and returns val * values in the original
    '''
    for i in range(len(lst)):
        for j in range(len(lst[i])):
            lst[i][j] = lst[i][j] * val
    return lst

def weighted_avg(lst):
    '''
        parameters: 2d list with one row of floats/weights, one row of floats/values
        returns: float
        does: computes the weighted average of the given list, assuming weights are in
              the first row and values in the second
    '''
    avg = 0
    for i in range(len(lst[0])):
        curr = (lst[0][i] * lst[1][i])
        avg += curr
    return avg

# This last one is a bonus, for funsies! Feel free to ignore
def sum_rows(lst):
    '''
        Parameters: 2d list of ints/floats
        Returns: 1d list of ints/floats
        Does: Sums each row of the given list, returns a list of sums
    '''
    sums = []
    for row in lst:
        curr_sum = sum(row)
        sums.append(curr_sum)
    return sums

def main():
    # Here in main, we're just calling the functions we've written to test them!
    # Mostly generating some random values to try out

    # Generate a 2d list with randomized values, and randomly-chosen number of
    # rows and columns.
    lst = []
    num_rows = random.randint(1, 5)
    num_cols = random.randint(1, 8)
    for i in range(num_rows):
        row = []
        for j in range(num_cols):
            row.append(random.randint(1, 200))
        lst.append(row)

    # Here is my list for testing...
    print(lst)

    # Call our functions! First, print row[0] for every row
    print("Printing the first value in every row...")
    print_row_first(lst)

    # Second, double all the values in the list and print out
    doubled = multiply_2d(lst, 2)
    print("\n\nThis doubled the values in my list...")
    print(doubled)

    # Third, make up a new list to test weighted average
    weights = [.25, .3, .35, .1, .05]
    values = [89, 87, 98, 90, 81]
    scores = [weights, values]
    weighted = weighted_avg(scores)
    print("Weighted average is...", weighted, "\n\n")

    # Fourth, just for fun, get the sum of every row
    row_summed = sum_rows(lst)
    print("Here is my list of sums of every row...")
    print(row_summed)

main()