leetcode面试经典150题-13. 罗马数字转整数

https://leetcode.cn/problems/roman-to-integer/description/?envType=study-plan-v2&envId=top-interview-150

GO

package leetcode150

import "testing"

/*
    romanMap := map[string]int{
            "I": 1,
            "V": 5,
            "X": 10,
            "L": 50,
            "C": 100,
            "D": 500,
            "M": 1000,
        }
*/
func TestRomanToInt(t *testing.T) {
    s := "MCMXCIV"
    res := romanToInt(s)
    println(res)
}

func romanToInt(s string) int {
    total := 0
    for i := 0; i < len(s); i++ {
        switch s[i] {
        case 'I':
            if i+1 < len(s) && s[i+1] == 'V' {
                total += 4
                i++
            } else if i+1 < len(s) && s[i+1] == 'X' {
                total += 9
                i++
            } else {
                total += 1
            }
        case 'V':
            total += 5
        case 'X':
            if i+1 < len(s) && s[i+1] == 'L' {
                total += 40
                i++
            } else if i+1 < len(s) && s[i+1] == 'C' {
                total += 90
                i++
            } else {
                total += 10
            }
        case 'L':
            total += 50
        case 'C':
            if i+1 < len(s) && s[i+1] == 'D' {
                total += 400
                i++
            } else if i+1 < len(s) && s[i+1] == 'M' {
                total += 900
                i++
            } else {
                total += 100
            }
        case 'D':
            total += 500
        case 'M':
            total += 1000
        }
    }
    return total
}