Final answer:
The time complexity of the given code snippet is O(n), where n is the input variable.
Step-by-step explanation:
The given code snippet is a for loop that iterates from 0 to n. Inside the loop, the variable sum is updated by adding the value of i to it. The time complexity of this code can be represented using Big O notation, which analyzes the performance of an algorithm as the input size grows. In this case, the time complexity is O(n), where n is the value of the input variable.