【leetcode每日刷题】12. Integer to Roman

Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M.

Symbol       Value
I             1
V             5
X             10
L             50
C             100
D             500
M             1000

For example, two is written as II in Roman numeral, just two one's added together. Twelve is written as, XII, which is simply X + II. The number twenty seven is written as XXVII, which is XX + V + II.

Roman numerals are usually written largest to smallest from left to right. However, the numeral for four is not IIII. Instead, the number four is written as IV. 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. There are six instances where subtraction is used:

I can be placed before V (5) and X (10) to make 4 and 9.
X can be placed before L (50) and C (100) to make 40 and 90.
C can be placed before D (500) and M (1000) to make 400 and 900.

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

Example 1:

Input: 3
Output: "III"

Example 2:

Input: 4
Output: "IV"

Example 3:

Input: 9
Output: "IX"

Example 4:

Input: 58
Output: "LVIII"
Explanation: L = 50, V = 5, III = 3.

Example 5:

Input: 1994
Output: "MCMXCIV"
Explanation: M = 1000, CM = 900, XC = 90 and IV = 4.

package main
import(
	"fmt"
)
type Dict struct{
	key string
	value int
}
func intToRoman(num int) string {
	var result string
	dict := []Dict{{"M",1000},{"CM",900},{"D",500},{"CD",400},{"C",100},{"XC",90},{"L",50},{"XL",40},{"X",10},{"IX",9},{"V",5},{"IV",4},{"I",1}}
	for _, v:= range dict{
		temp := num - v.value
		for temp >= 0 && num > 0{
			num = num - v.value
			result = result + v.key
			temp = num - v.value
		}
		if num == 0{
			break
		}
	}
	return result
}
func main(){
	fmt.Println(intToRoman(1994))
}

字典本来使用golang中自带的字典map表示的，但是map顺序会乱，所以使用结构体数组代替，会按顺序进行匹配

【leetcode每日刷题】12. Integer to Roman

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