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56 lines
2.1 KiB
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56 lines
2.1 KiB
HTML
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<p>Roman numerals are represented by seven different symbols: <code>I</code>, <code>V</code>, <code>X</code>, <code>L</code>, <code>C</code>, <code>D</code> and <code>M</code>.</p>
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<pre>
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<strong>Symbol</strong> <strong>Value</strong>
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I 1
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V 5
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X 10
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L 50
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C 100
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D 500
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M 1000</pre>
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<p>For example, <code>2</code> is written as <code>II</code> in Roman numeral, just two one's added together. <code>12</code> is written as <code>XII</code>, which is simply <code>X + II</code>. The number <code>27</code> is written as <code>XXVII</code>, which is <code>XX + V + II</code>.</p>
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<p>Roman numerals are usually written largest to smallest from left to right. However, the numeral for four is not <code>IIII</code>. Instead, the number four is written as <code>IV</code>. Because the one is before the five we subtract it making four. The same principle applies to the number nine, which is written as <code>IX</code>. There are six instances where subtraction is used:</p>
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<ul>
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<li><code>I</code> can be placed before <code>V</code> (5) and <code>X</code> (10) to make 4 and 9. </li>
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<li><code>X</code> can be placed before <code>L</code> (50) and <code>C</code> (100) to make 40 and 90. </li>
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<li><code>C</code> can be placed before <code>D</code> (500) and <code>M</code> (1000) to make 400 and 900.</li>
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</ul>
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<p>Given an integer, convert it to a roman numeral.</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> num = 3
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<strong>Output:</strong> "III"
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<strong>Explanation:</strong> 3 is represented as 3 ones.
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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> num = 58
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<strong>Output:</strong> "LVIII"
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<strong>Explanation:</strong> L = 50, V = 5, III = 3.
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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> num = 1994
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<strong>Output:</strong> "MCMXCIV"
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<strong>Explanation:</strong> M = 1000, CM = 900, XC = 90 and IV = 4.
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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 <= num <= 3999</code></li>
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</ul>
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