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36 lines
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36 lines
2.2 KiB
HTML
<p>There are <code>n</code> cars traveling at different speeds in the same direction along a one-lane road. You are given an array <code>cars</code> of length <code>n</code>, where <code>cars[i] = [position<sub>i</sub>, speed<sub>i</sub>]</code> represents:</p>
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<ul>
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<li><code>position<sub>i</sub></code> is the distance between the <code>i<sup>th</sup></code> car and the beginning of the road in meters. It is guaranteed that <code>position<sub>i</sub> < position<sub>i+1</sub></code>.</li>
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<li><code>speed<sub>i</sub></code> is the initial speed of the <code>i<sup>th</sup></code> car in meters per second.</li>
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</ul>
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<p>For simplicity, cars can be considered as points moving along the number line. Two cars collide when they occupy the same position. Once a car collides with another car, they unite and form a single car fleet. The cars in the formed fleet will have the same position and the same speed, which is the initial speed of the <strong>slowest</strong> car in the fleet.</p>
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<p>Return an array <code>answer</code>, where <code>answer[i]</code> is the time, in seconds, at which the <code>i<sup>th</sup></code> car collides with the next car, or <code>-1</code> if the car does not collide with the next car. Answers within <code>10<sup>-5</sup></code> of the actual answers are accepted.</p>
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<p> </p>
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<p><strong>Example 1:</strong></p>
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<pre>
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<strong>Input:</strong> cars = [[1,2],[2,1],[4,3],[7,2]]
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<strong>Output:</strong> [1.00000,-1.00000,3.00000,-1.00000]
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<strong>Explanation:</strong> After exactly one second, the first car will collide with the second car, and form a car fleet with speed 1 m/s. After exactly 3 seconds, the third car will collide with the fourth car, and form a car fleet with speed 2 m/s.
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</pre>
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<p><strong>Example 2:</strong></p>
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<pre>
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<strong>Input:</strong> cars = [[3,4],[5,4],[6,3],[9,1]]
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<strong>Output:</strong> [2.00000,1.00000,1.50000,-1.00000]
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</pre>
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<p> </p>
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<p><strong>Constraints:</strong></p>
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<ul>
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<li><code>1 <= cars.length <= 10<sup>5</sup></code></li>
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<li><code>1 <= position<sub>i</sub>, speed<sub>i</sub> <= 10<sup>6</sup></code></li>
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<li><code>position<sub>i</sub> < position<sub>i+1</sub></code></li>
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</ul>
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