\u4eca\u5929\u505a\u5b8c \u00a0Roman to Integer \u8fd9\u9053\u9898\u540e\u611f\u89c9\u8fd0\u884c\u65f6\u95f4\u7a0d\u957f\u5c31\u5f00\u59cb\u4e86\u4f18\u5316\u4ee3\u7801\u3002\u7136\u540e\u5c31\u53d1\u73b0\u8d8a\u4f18\u5316\u8d8a\u4e0d\u79d1\u5b66\uff01\u62ff\u6765\u4e2d\u6587\u7248\u7684 leetCode \u7f51\u7ad9\u6765\u8fd0\u884c\u53d1\u73b0\u66f4\u52a0\u795e\u5947\u3002<\/p>\n\n\n\n
\u9898\u76ee\u8be6\u60c5<\/h3>\n\n\n\n
Roman numerals are represented by seven different symbols: I<\/code>, V<\/code>, X<\/code>, L<\/code>, C<\/code>, D<\/code> and M<\/code>.<\/p>\n\n\n\n
For example, two is written as II<\/code> in Roman numeral, just two one’s added together. Twelve is written as, XII<\/code>, which is simply X<\/code> + II<\/code>. The number twenty seven is written as XXVII<\/code>, which is XX<\/code> + V<\/code> + II<\/code>.<\/p>\n\n\n\n
Roman numerals are usually written largest to smallest from left to right. However, the numeral for four is not IIII<\/code>. Instead, the number four is written as 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 IX<\/code>. There are six instances where subtraction is used:<\/p>\n\n\n\n
I<\/code> can be placed before V<\/code> (5) and X<\/code> (10) to make 4 and 9. <\/li>
X<\/code> can be placed before L<\/code> (50) and C<\/code> (100) to make 40 and 90. <\/li>
C<\/code> can be placed before D<\/code> (500) and M<\/code> (1000) to make 400 and 900.<\/li><\/ul>\n\n\n\n
Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999.<\/p>\n\n\n\n
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