"""
-------------------------------------------------------
for and while comparison
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Author:  David Brown
ID:      123456789
Email:   dbrown@wlu.ca
__updated__ = "2023-06-11"
-------------------------------------------------------
"""
# Constants
SEP = "-" * 60


def wrong_for(values, key):
    """
    Linear search for first occurrence of key in values.
    ERROR: may return -1 inappropriately.
    """
    for i in range(len(values)):
        if values[i] == key:
            index = i
        else:
            index = -1
    return index


def last_for(values, key):
    """
    Linear search for first occurrence of key in values.
    ERROR: may return last index if key appears more than once.
    """
    index = -1

    for i in range(len(values)):
        if values[i] == key:
            index = i
    return index


def inefficient_for(values, key):
    """
    Linear search for first occurrence of key in values.
    INEFFICIENT: loops through all of values even if key already found.
    """
    index = -1

    for i in range(len(values)):
        if index == -1 and values[i] == key:
            index = i
    return index


def break_for(values, key):
    """
    Linear search for first occurrence of key in values.
    LIES: for loop claims to visit all of values, break short circuits that.
    """
    index = -1

    for i in range(len(values)):

        if values[i] == key:
            index = i
            break
    return index


def while_search(values, key):
    """
    Linear search for first occurrence of key in values.
    Correct, efficient, truthful. Minimizes work done in body of loop. 
    """
    i = 0

    while i < len(values) and values[i] != key:
        i += 1

    if i < len(values):
        index = i
    else:
        index = -1
    return index


# for testing
if __name__ == "__main__":
    print(SEP)
    print("Testing wrong_for")
    values = [1, 2, 3, 4, 5]
    key = 5
    index = wrong_for(values, key)
    print(f"wrong_for({values}, {key}) -> {index}")
    values = [1, 2, 3, 4, 5]
    key = 3
    index = wrong_for(values, key)
    print(f"wrong_for({values}, {key}) -> {index}")
    print(SEP)
    print("Testing last_for")
    values = [1, 2, 3, 4, 5]
    key = 3
    index = last_for(values, key)
    print(f"last_for({values}, {key}) -> {index}")
    values = values * 2
    key = 3
    index = last_for(values, key)
    print(f"last_for({values}, {key}) -> {index}")
    print(SEP)
    print("Testing inefficient_for")
    values = [1, 2, 3, 4, 5]
    key = 3
    index = inefficient_for(values, key)
    print(f"inefficient_for({values}, {key}) -> {index}")
    print(SEP)
    print("Testing while_search")
    values = [1, 2, 3, 4, 5]
    key = 3
    index = while_search(values, key)
    print(f"while_search({values}, {key}) -> {index}")
    print(SEP)
    print("Done")