Roman to Integer

RomanInteger.go

func romanToInt(input string) int {
    currentPoint := len(input) - 1
    result := 0
    
	for currentPoint > 0 {
		right := mapInt(getChar(currentPoint, input))
		left := mapInt(getChar(currentPoint-1, input))

		if right == left {
			if result == 0 {
				result += right + left
			} else {
				result += left
			}
		} else {
            
			if currentPoint != (len(input) - 1) { 
				right = result //若當前指針不是最後一個值，則將目前的result當作right去跟left計算
			}
            
			if right > left {
				result = right - left
			} else {
				result = right + left
			}
		}

        currentPoint -= 1
	}
    
    return result   
}


func getChar(v int, input string) rune {
	inputRunes := []rune(input)
	return inputRunes[v]
}


func mapInt(v rune) int {
	romanNumberMap := map[rune]int{
		'I': 1,
		'V': 5,
		'X': 10,
		'L': 50,
		'C': 100,
		'D': 500,
		'M': 1000,
	}
	return romanNumberMap[v]
}