<p>You are given an integer array <code>cost</code> where <code>cost[i]</code> is the cost of <code>i<sup>th</sup></code> step on a staircase. Once you pay the cost, you can either climb one or two steps.</p> <p>You can either start from the step with index <code>0</code>, or the step with index <code>1</code>.</p> <p>Return <em>the minimum cost to reach the top of the floor</em>.</p> <p> </p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> cost = [10,<u>15</u>,20] <strong>Output:</strong> 15 <strong>Explanation:</strong> You will start at index 1. - Pay 15 and climb two steps to reach the top. The total cost is 15. </pre> <p><strong class="example">Example 2:</strong></p> <pre> <strong>Input:</strong> cost = [<u>1</u>,100,<u>1</u>,1,<u>1</u>,100,<u>1</u>,<u>1</u>,100,<u>1</u>] <strong>Output:</strong> 6 <strong>Explanation:</strong> You will start at index 0. - Pay 1 and climb two steps to reach index 2. - Pay 1 and climb two steps to reach index 4. - Pay 1 and climb two steps to reach index 6. - Pay 1 and climb one step to reach index 7. - Pay 1 and climb two steps to reach index 9. - Pay 1 and climb one step to reach the top. The total cost is 6. </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>2 <= cost.length <= 1000</code></li> <li><code>0 <= cost[i] <= 999</code></li> </ul>