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48 lines
2.1 KiB
HTML
48 lines
2.1 KiB
HTML
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<p>You are given an array of <code>n</code> strings <code>strs</code>, all of the same length.</p>
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<p>We may choose any deletion indices, and we delete all the characters in those indices for each string.</p>
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<p>For example, if we have <code>strs = ["abcdef","uvwxyz"]</code> and deletion indices <code>{0, 2, 3}</code>, then the final array after deletions is <code>["bef", "vyz"]</code>.</p>
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<p>Suppose we chose a set of deletion indices <code>answer</code> such that after deletions, the final array has <strong>every string (row) in lexicographic</strong> order. (i.e., <code>(strs[0][0] <= strs[0][1] <= ... <= strs[0][strs[0].length - 1])</code>, and <code>(strs[1][0] <= strs[1][1] <= ... <= strs[1][strs[1].length - 1])</code>, and so on). Return <em>the minimum possible value of</em> <code>answer.length</code>.</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> strs = ["babca","bbazb"]
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<strong>Output:</strong> 3
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<strong>Explanation:</strong> After deleting columns 0, 1, and 4, the final array is strs = ["bc", "az"].
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Both these rows are individually in lexicographic order (ie. strs[0][0] <= strs[0][1] and strs[1][0] <= strs[1][1]).
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Note that strs[0] > strs[1] - the array strs is not necessarily in lexicographic order.</pre>
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<p><strong>Example 2:</strong></p>
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<pre>
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<strong>Input:</strong> strs = ["edcba"]
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<strong>Output:</strong> 4
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<strong>Explanation:</strong> If we delete less than 4 columns, the only row will not be lexicographically sorted.
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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> strs = ["ghi","def","abc"]
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<strong>Output:</strong> 0
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<strong>Explanation:</strong> All rows are already lexicographically sorted.
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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>n == strs.length</code></li>
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<li><code>1 <= n <= 100</code></li>
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<li><code>1 <= strs[i].length <= 100</code></li>
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<li><code>strs[i]</code> consists of lowercase English letters.</li>
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</ul>
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<ul>
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<li> </li>
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</ul>
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