Day 5, Part 1

#extract the code from the file and load it into an array for processing
input1 = open("intcode.txt", "r")
code = input1.read()
input1.close()
code = code.split(",")

#the array elements are currently strings; turn them into integers
for i in range(len(code)):
    code[i] = int(code[i])

#function to return a five-element array to represent the intcode
def intcodeArray(int1):
    intcode = list(str(int1))
    if(len(intcode)<5):
        for i in range(5-len(intcode)):
            intcode.insert(0,"0")
    for i in range(len(intcode)):
        intcode[i] = int(intcode[i])
    return intcode

##inst[4] and inst[3] are the opcode
##inst[2] is the mode of the first parameter
##inst[1] is the mode of the second parameter

#function to return the value of a position, given its mode
def value(mode, position):
    val = 0
    if(mode==0):
        val = code[code[position]]
    else:
        val = code[position]
    return val

pos = 0

#run the intcode
while(code[pos]!=99):

    inst = intcodeArray(code[pos])

    #add two values
    if(inst[4]==1):

        two = pos+1
        three = pos+2
        four = code[pos+3]

        code[four] = value(inst[2],two) + value(inst[1],three)
        pos += 4

    #multiply two values
    elif(inst[4]==2):

        two = pos+1
        three = pos+2
        four = code[pos+3]

        code[four] = value(inst[2],two) * value(inst[1],three)
        pos += 4

    #take an input value
    elif(inst[4]==3):
        print("What is your input value?")
        choice = input()
        choice = int(choice)
        if(inst[2]==0):
            code[code[pos+1]] = choice
        else:
            code[pos+1] = choice
        pos += 2

    #print an output value
    elif(inst[4]==4):
        print(value(inst[2],(pos+1)))
        pos += 2