Given a sequence of positive integers `nums` and an integer `k`, return whether there is a continuous sequence of `nums` that sums up to exactly `k`.\n\n**Example 1:**\n``` \nInput: nums = [23, 5, 4, 7, 2, 11], k = 20\nOutput: true\nOutput: 7 + 2 + 11 = 20\n```\n\n**Example 2:**\n```\nInput: nums = [1, 3, 5, 23, 2], k = 8\nOutput: true\nExplanation: 3 + 5 = 8\n```\n\n**Example 3:**\n```\nInput: nums = [1, 3, 5, 23, 2], k = 7\nOutput: false\nExplanation: because no sequence in this array adds up to 7.\n```

Given a sequence of positive integers nums and an integer k, return whether there is a continuous sequence of nums that sums up to exactly k.\n\nExample 1:\n\nI