罗马数字和整数互相转化

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    <meta name="author" content="杨欣">
    <title></title>
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<body>

    <script>
        // 整数转罗马数字
        function intoRoman(num) {
            let keys = [1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1]
            let values = ['M', 'CM', 'D', 'CD', 'C', 'XC', 'L', 'XL', 'X', 'IX', 'V', 'IV', 'I']
            let res = ''
            for (let i = 0; i < keys.length; i++) {
                while (num >= keys[i]) {
                    num = num - keys[i]
                    res += values[i]
                }
            }
            return res
        }
        console.log(intoRoman(3));

        // 罗马数字转整数
        var romanToInt = function (s) {
            var hashNum = {
                "I": 1,
                "V": 5,
                "X": 10,
                "L": 50,
                "C": 100,
                "D": 500,
                "M": 1000
            }
            var result = 0;
            for (let i = 0; i < s.length; i++) {
                hashNum[s[i]] < hashNum[s[i + 1]] ? result -= hashNum[s[i]] : result += hashNum[s[i]]
            }
            return result;
        };
        console.log(romanToInt('III'));

    </script>
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原文地址:https://www.cnblogs.com/samsara-yx/p/12804337.html