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42 lines
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42 lines
1.5 KiB
HTML
<p>You are given an integer array <code>prices</code> representing the daily price history of a stock, where <code>prices[i]</code> is the stock price on the <code>i<sup>th</sup></code> day.</p>
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<p>A <strong>smooth descent period</strong> of a stock consists of <strong>one or more contiguous</strong> days such that the price on each day is <strong>lower</strong> than the price on the <strong>preceding day</strong> by <strong>exactly</strong> <code>1</code>. The first day of the period is exempted from this rule.</p>
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<p>Return <em>the number of <strong>smooth descent periods</strong></em>.</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> prices = [3,2,1,4]
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<strong>Output:</strong> 7
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<strong>Explanation:</strong> There are 7 smooth descent periods:
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[3], [2], [1], [4], [3,2], [2,1], and [3,2,1]
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Note that a period with one day is a smooth descent period by the definition.
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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> prices = [8,6,7,7]
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<strong>Output:</strong> 4
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<strong>Explanation:</strong> There are 4 smooth descent periods: [8], [6], [7], and [7]
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Note that [8,6] is not a smooth descent period as 8 - 6 ≠ 1.
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</pre>
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<p><strong>Example 3:</strong></p>
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<pre>
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<strong>Input:</strong> prices = [1]
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<strong>Output:</strong> 1
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<strong>Explanation:</strong> There is 1 smooth descent period: [1]
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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 <= prices.length <= 10<sup>5</sup></code></li>
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<li><code>1 <= prices[i] <= 10<sup>5</sup></code></li>
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</ul>
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