Leetcode 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 beforeV
(5) andX
(10) to make 4 and 9.X
can be placed beforeL
(50) andC
(100) to make 40 and 90.C
can be placed beforeD
(500) andM
(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: C = 100, L = 50, XXX = 30 and III = 3.
Example 5:
Input: 1994 Output: "MCMXCIV" Explanation: M = 1000, CM = 900, XC = 90 and IV = 4.
這個題考察的是數字和字元的轉換,看懂了規則模擬出來就可以的。
1)
class Solution {
public String intToRoman(int num) {
StringBuilder ss = new StringBuilder();
int flag = 0;
while(num >= 1000){
ss.append("M");
num-=1000;
}
while(num >= 900){
ss.append("CM");
num-=900;
}
while(num >= 500){
ss.append("D");
num-=500;
}
while(num >= 400){
ss.append("CD");
num-=400;
}
while(num >= 100){
ss.append("C");
num-=100;
}
while(num >= 90){
ss.append("XC");
num-=90;
}
while(num >= 50){
ss.append("L");
num-=50;
}
while(num >= 40){
ss.append("XL");
num-=40;
}
while(num >= 10){
ss.append("X");
num-=10;
}
while(num >= 9){
ss.append("IX");
num-=9;
}
while(num >= 5){
ss.append("V");
num-=5;
}
while(num >= 4){
ss.append("IV");
num-=4;
}
while(num >= 1){
ss.append("I");
num-=1;
}
return ss.toString();
}
}
2)
class Solution {
public String intToRoman(int num){
String[] letters = {"M","CM","D","CD","C","XC","L","XL","X","IX","V","IV","I"};
int[] values = {1000,900,500,400,100,90,50,40,10,9,5,4,1};
int index = 0;
StringBuffer sb = new StringBuffer();
while(num>0){
if(num>=values[index]){
sb.append(letters[index]);
num -= values[index];
}else{
index ++;
}
}
return sb.toString();
}
}
相關文章
- Leetcode 12. Integer to RomanLeetCode
- Leetcode Integer to RomanLeetCode
- leetcode Roman to IntegerLeetCode
- [LeetCode] Roman to IntegerLeetCode
- LeetCode - 解題筆記 - 12 - Integer to RomanLeetCode筆記
- Leetcode 13 Roman to IntegerLeetCode
- Leetcode-Roman to IntegerLeetCode
- Leetcode-Integer to RomanLeetCode
- Integer to Roman leetcode javaLeetCodeJava
- Roman to Integer leetcode javaLeetCodeJava
- LeetCode Integer to Roman(012)解法總結LeetCode
- [Swift LeetCode]13. Roman to IntegerSwiftLeetCode
- 13. Roman to Integer--LeetCode RecordLeetCode
- LeetCode Roman to Integer(013)解法總結LeetCode
- LeetCode 13. Roman to Integer C語言LeetCodeC語言
- [LeetCode] Integer to Roman 整數轉化成羅馬數字LeetCode
- [LeetCode] Roman to Integer 羅馬數字轉化成整數LeetCode
- leetcode Reverse IntegerLeetCode
- Leetcode 7 Reverse IntegerLeetCode
- LeetCode-Integer ReplacementLeetCode
- LeetCode-Integer BreaksLeetCode
- Reverse Integer leetcode javaLeetCodeJava
- Integer128==128?falseFalse
- Leetcode 273 Integer to English WordsLeetCode
- Leetcode-Problem:Reverse IntegerLeetCode
- LeetCode-Integer to English WordsLeetCode
- leetcode String to Integer (atoi)LeetCode
- Leetcode - String to Integer (atoi)LeetCode
- Leetcode 8 String to Integer (atoi)LeetCode
- LeetCode 第 7 題(Reverse Integer)LeetCode
- LeetCode 第 343 題 (Integer Break)LeetCode
- String to Integer (atoi) leetcode javaLeetCodeJava
- [leetcode] 1394. Find Lucky Integer in an ArrayLeetCode
- [LeetCode] Reverse Integer 翻轉整數LeetCode
- LeetCode Reverse Integer(007)解法總結LeetCode
- LeetCode - 解題筆記 - 7 - Reverse IntegerLeetCode筆記
- 1211Bug with integer literals in PLSQLSQL
- 【LeetCode從零單排】No.7 Reverse IntegerLeetCode