FDS (KR) - Ass 3 (Lin and Sent Search)

def createList():
    result = []
    n = int(input("Enter the number of students: "))
    print("Enter the Roll Numbers: ")
    for i in range(0, n):
        roll = int(input())
        result.append(roll)
    return result

# Linear Search
def linearSearch(list):
    flag = 0
    index = 0
    key = int(input("Enter the Roll Number to be checked: "))
    for i in range(0, len(list) - 1):
        if list[i] == key:
            flag = 1
            index = i
            break
        else:
            flag = 0
    if (flag == 1):
        print(f"Roll Number: {key} was PRESENT at Index {index}")
    elif (flag == 0):
        print(f"Roll Number: {key} was ABSENT")


## Sentinel Search
def sentinelSearch(list):
    key = int(input("Enter the Roll Number to be checked: "))
    size = len(list)
    last = list[size-1]
    list[size-1] = key
    i = 0
    index = 0
    flag = 0
    while list[i] != key:
        i += 1
    list[size-1] = last
    if ((i < (size - 1)) or (key == list[size - 1])):
        flag = 1
    else:
        flag = 0

    if (flag == 1):
        print(f"Roll Number: {key} was PRESENT at Index {index}")
    elif (flag == 0):
        print(f"Roll Number: {key} was ABSENT")

rolls = createList()

while (true):
    print("--------- MENU ----------")
    print("CHOICE 1: Linear Search")
    print("CHOICE 2: Sentinel Search")
    print("CHOICE 3: Break")
    choice = input("Enter a choice: ")
    if choice == 1:
        linearSearch(rolls)
    elif choice == 2:
        sentinelSearch(rolls)
    elif choice == 3:
        break
    else:
        print("Invalid Choice")