แปลงตัวเลข 0 ถึง 2³¹-1 เป็นคำอ่านภาษาอังกฤษ เช่น 512 → "Five Hundred Twelve"
ขั้นตอนการแก้ปัญหา
- เตรียมลิสต์คำ:
less_than_20(1-19),tens(20,30,...90),thousands("", "Thousand", "Million", "Billion") - ฟังก์ชัน
helper(n)แปลง 3 หลัก:n == 0→ ""n < 20→less_than_20[n]n < 100→tens[n//10] + helper(n%10)- อื่น →
less_than_20[n//100] + " Hundred " + helper(n%100)
- หลักหลัก: วนกลุ่ม 3 หลัก (pairs of 3 digits) ใช้
helperและต่อthousands[i]
การติดตั้งใน Python
class Solution:
less_than_20 = ["","One","Two","Three","Four","Five","Six","Seven","Eight","Nine","Ten",
"Eleven","Twelve","Thirteen","Fourteen","Fifteen","Sixteen","Seventeen","Eighteen","Nineteen"]
tens = ["","Ten","Twenty","Thirty","Forty","Fifty","Sixty","Seventy","Eighty","Ninety"]
thousands = ["","Thousand","Million","Billion"]
def numberToWords(self, num):
if num == 0:
return "Zero"
def helper(n):
if n == 0:
return ""
elif n < 20:
return self.less_than_20[n] + " "
elif n < 100:
return self.tens[n//10] + " " + helper(n%10)
else:
return self.less_than_20[n//100] + " Hundred " + helper(n%100)
ans = ""
i = 0
while num > 0:
if num % 1000 != 0:
ans = helper(num % 1000) + self.thousands[i] + " " + ans
num //= 1000
i += 1
return ans.strip()
ob = Solution()
print(ob.numberToWords(512)) # Five Hundred Twelve
print(ob.numberToWords(7835271)) # Seven Million Eight Hundred Thirty Five Thousand Two Hundred Seventy One
อินพุต / เอาต์พุต
Input: 512, 7835271 Output: Five Hundred Twelve, Seven Million Eight Hundred Thirty Five Thousand Two Hundred Seventy One
