{ "data": { "question": { "questionId": "1324", "questionFrontendId": "1706", "boundTopicId": null, "title": "Where Will the Ball Fall", "titleSlug": "where-will-the-ball-fall", "content": "

You have a 2-D grid of size m x n representing a box, and you have n balls. The box is open on the top and bottom sides.

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Each cell in the box has a diagonal board spanning two corners of the cell that can redirect a ball to the right or to the left.

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We drop one ball at the top of each column of the box. Each ball can get stuck in the box or fall out of the bottom. A ball gets stuck if it hits a "V" shaped pattern between two boards or if a board redirects the ball into either wall of the box.

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Return an array answer of size n where answer[i] is the column that the ball falls out of at the bottom after dropping the ball from the ith column at the top, or -1 if the ball gets stuck in the box.

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Example 1:

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\"\"

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\nInput: grid = [[1,1,1,-1,-1],[1,1,1,-1,-1],[-1,-1,-1,1,1],[1,1,1,1,-1],[-1,-1,-1,-1,-1]]\nOutput: [1,-1,-1,-1,-1]\nExplanation: This example is shown in the photo.\nBall b0 is dropped at column 0 and falls out of the box at column 1.\nBall b1 is dropped at column 1 and will get stuck in the box between column 2 and 3 and row 1.\nBall b2 is dropped at column 2 and will get stuck on the box between column 2 and 3 and row 0.\nBall b3 is dropped at column 3 and will get stuck on the box between column 2 and 3 and row 0.\nBall b4 is dropped at column 4 and will get stuck on the box between column 2 and 3 and row 1.\n
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Example 2:

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\nInput: grid = [[-1]]\nOutput: [-1]\nExplanation: The ball gets stuck against the left wall.\n
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Example 3:

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\nInput: grid = [[1,1,1,1,1,1],[-1,-1,-1,-1,-1,-1],[1,1,1,1,1,1],[-1,-1,-1,-1,-1,-1]]\nOutput: [0,1,2,3,4,-1]\n
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Constraints:

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