标签:sam convert one leetcode symbol dde data making however
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 a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999.
Example 1:
Input: "III" Output: 3
Example 2:
Input: "IV" Output: 4
Example 3:
Input: "IX" Output: 9
Example 4:
Input: "LVIII" Output: 58 Explanation: L = 50, V= 5, III = 3.
Example 5:
Input: "MCMXCIV" Output: 1994 Explanation: M = 1000, CM = 900, XC = 90 and IV = 4.
1 class Solution { 2 public: 3 int romanToInt(string s) { 4 int ans = 0; 5 int top = 0; 6 int len = s.length(); 7 while(top<len){ 8 if(s[top]==‘M‘){ 9 ans += 1000; 10 top++; 11 } 12 else if(s[top]==‘D‘){ 13 ans += 500; 14 top++; 15 } 16 else if(s[top]==‘C‘){ 17 if(s[top+1]==‘D‘){ 18 ans += 400; 19 top+=2; 20 } 21 else if(s[top+1]==‘M‘){ 22 ans +=900; 23 top+=2; 24 } 25 else { 26 ans += 100; 27 top++; 28 } 29 } 30 else if(s[top]==‘L‘){ 31 ans+=50; 32 top++; 33 } 34 else if(s[top]==‘X‘){ 35 if(s[top+1]==‘C‘){ 36 ans += 90; 37 top+=2; 38 } 39 else if(s[top+1]==‘L‘){ 40 ans += 40; 41 top+=2; 42 } 43 else { 44 ans += 10; 45 top++; 46 } 47 } 48 else if(s[top]==‘V‘){ 49 ans+=5; 50 top++; 51 } 52 else if(s[top]==‘I‘){ 53 if(s[top+1]==‘X‘){ 54 ans += 9; 55 top+=2; 56 } 57 else if(s[top+1]==‘V‘){ 58 ans += 4; 59 top+=2; 60 } 61 else { 62 ans += 1; 63 top++; 64 } 65 } 66 } 67 return ans; 68 } 69 };
Leetcode 13. Roman to Integer(水)
标签:sam convert one leetcode symbol dde data making however
原文地址:https://www.cnblogs.com/shanyr/p/11437973.html