文章--LeetCode算法-- RomantoInteger

目录

• RomantoInteger
  • 问题描述
  • 实例
  • 实现代码

RomantoInteger

问题描述

Given a roman numeral, convert it to an integer.
Input is guaranteed to be within the range from 1 to 3999.

实例

• Example 1:

Input: "III"

Output: 3

• Example 2:

Input: "IV"

Output: 4

• Example 3:

Input: "IX"

Output: 9

实现代码

   public class Solution {
        public int romanToInt(String s) {
            int sum = 0;
            if (s.indexOf("IV") != -1) {
                sum -= 2;
            }
            if (s.indexOf("IX") != -1) {
                sum -= 2;
            }
            if (s.indexOf("XL") != -1) {
                sum -= 20;
            }
            if (s.indexOf("XC") != -1) {
                sum -= 20;
            }
            if (s.indexOf("CD") != -1) {
                sum -= 200;
            }
            if (s.indexOf("CM") != -1) {
                sum -= 200;
            }
            char c[] = s.toCharArray();
            int count = 0;
            for (; count <= s.length() - 1; count++) {
                if (c[count] == 'M')
                    sum += 1000;
                if (c[count] == 'D')
                    sum += 500;
                if (c[count] == 'C')
                    sum += 100;
                if (c[count] == 'L')
                    sum += 50;
                if (c[count] == 'X')
                    sum += 10;
                if (c[count] == 'V')
                    sum += 5;
                if (c[count] == 'I')
                    sum += 1;
            }
            return sum;
        }
    }