题目描述
Given a roman numeral, convert it to an integer.
Input is guaranteed to be within the range from 1 to 3999.
思路：
- 题意：罗马数字最多只有一个“左边修饰”
- 有左边修饰进两位，默认进一位，计算值，并累加。
解：
package main
import "fmt"
func romanToInt(s string) int {
units := make(map[rune]int, 7)
units['I'] = 1
units['V'] = 5
units['X'] = 10
units['L'] = 50
units['C'] = 100
units['D'] = 500
units['M'] = 1000
res := 0
sSlice := []rune(s)
i :=0
for ; i < len(sSlice)-1; {
if units[sSlice[i]] < units[sSlice[i+1]] {
res += units[sSlice[i+1]] - units[sSlice[i]]
i = i+2
}else {
res += units[sSlice[i]]
i++
}
}
if i != len(sSlice){
res += units[sSlice[i]]
}
return res
}
func main() {
s := "III"
res := romanToInt(s)
fmt.Print(res)
}
