Day 2 challenge

day2/day2.py

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+def interpret_intcode(input_prog):
+    # Instruction pointer: index of the next element to be executed
+    ip = 0
+    while ip < len(input_prog):
+        instruction = input_prog[ip]
+        if instruction == 99:
+            break
+
+        elif instruction == 1:
+            # The operands to sum are at the memory location ip+1 and ip+2.
+            operands = (input_prog[input_prog[ip + 1]], input_prog[input_prog[ip + 2]])
+            result = sum(operands)
+            target = input_prog[ip + 3]
+            input_prog[target] = result
+            ip += 4
+
+        elif instruction == 2:
+            # The operands to multiply are at the memory location ip+1 and ip+2.
+            operands = (input_prog[input_prog[ip + 1]], input_prog[input_prog[ip + 2]])
+            result = operands[0] * operands[1]
+            target = input_prog[ip + 3]
+            input_prog[target] = result
+            ip += 4
+
+
+def tests():
+    inputs = (
+        [1, 0, 0, 0, 99],  # ADD 1 + 1 to location 0
+        [2, 3, 0, 3, 99],  # MUL 2 * 3 to location 3
+        [2, 4, 4, 5, 99, 0],
+        [1, 1, 1, 4, 99, 5, 6, 0, 99],
+    )
+    expected_outputs = (
+        [2, 0, 0, 0, 99],  # 1 + 1 = 2
+        [2, 3, 0, 6, 99],  # 3 * 2 = 6
+        [2, 4, 4, 5, 99, 9801],  # 99 * 99 = 9801
+        [30, 1, 1, 4, 2, 5, 6, 0, 99],
+    )
+    for i, inp in enumerate(inputs):
+        result = inp[:]
+        interpret_intcode(result)
+        assert (
+            result == expected_outputs[i]
+        ), f"Expected output for {inp} is {expected_outputs[i]}, but found {result} instead."
+    print("All tests passed.")
+
+
+def run_program(memory, noun, verb):
+    memory[1] = noun
+    memory[2] = verb
+    interpret_intcode(memory)
+    return memory[0]
+
+
+if __name__ == "__main__":
+    tests()
+    with open("input.txt") as inp:
+        memory = [int(x) for x in inp.readline().strip().split(",")]
+        # Pass a copy to avoid modifying the original memory
+        print("Part 1 answer: ", run_program(memory[:], 12, 2))
+
+        # Part 2
+        result = 0
+        for verb in range(99):
+            for noun in range(99):
+                if run_program(memory[:], noun, verb) == 19690720:
+                    print(f"Part 2: noun={noun}, verb={verb}")
+                    print("Result = ", 100 * noun + verb)
+                    break

day2/input.txt

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+1,0,0,3,1,1,2,3,1,3,4,3,1,5,0,3,2,1,13,19,1,9,19,23,1,6,23,27,2,27,9,31,2,6,31,35,1,5,35,39,1,10,39,43,1,43,13,47,1,47,9,51,1,51,9,55,1,55,9,59,2,9,59,63,2,9,63,67,1,5,67,71,2,13,71,75,1,6,75,79,1,10,79,83,2,6,83,87,1,87,5,91,1,91,9,95,1,95,10,99,2,9,99,103,1,5,103,107,1,5,107,111,2,111,10,115,1,6,115,119,2,10,119,123,1,6,123,127,1,127,5,131,2,9,131,135,1,5,135,139,1,139,10,143,1,143,2,147,1,147,5,0,99,2,0,14,0