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, 2 is written as II in Roman numeral, just two ones added together. 12 is written as XII, which is simply X + II. The number 27 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.
Example 1:
Input: s = "III " Output: 3 Explanation: III = 3.
Example 2:
Input: s = "LVIII " Output: 58 Explanation: L = 50, V= 5, III = 3.
Example 3:
Input: s = "MCMXCIV " Output: 1994 Explanation: M = 1000, CM = 900, XC = 90 and IV = 4.
Constraints:
1 <= s.length <= 15s contains only the characters ('I', 'V', 'X', 'L', 'C', 'D', 'M').s is a valid roman numeral in the range [1, 3999].program main
implicit none
character(len=10), parameter :: I = "I", V = "V", X = "X", L = "L", &
C = "C", D = "D", M = "M"
character(len=*) :: s
integer :: n
call get_command_argument(1, s)
read(s, *) n
write(*, "(A)", advance="no") decode(n)
contains
function decode(n) result(roman)
implicit none
integer, intent(in) :: n
character(len=:), allocatable :: roman
if (n == 1) then
allocate(character(len=1) :: roman)
roman = I
else if (n == 5) then
allocate(character(len=1) :: roman)
roman = V
else if (n == 10) then
allocate(character(len=1) :: roman)
roman = X
else if (n == 50) then
allocate(character(len=1) :: roman)
roman = L
else if (n == 100) then
allocate(character(len=1) :: roman)
roman = C
else if (n == 500) then
allocate(character(len=1) :: roman)
roman = D
else if (n == 1000) then
allocate(character(len=1) :: roman)
roman = M
else if (n > 1000) then
allocate(character(len=len(decode(n / 1000))+1) :: roman)
roman = decode(n / 1000) // M
n = mod(n, 1000)
if (n > 0) then
allocate(character(len=len(roman)+len(decode(n))) :: roman)
roman = roman // decode(n)
end if
end if
end function decode
end program maintemp.f95:6:25:
6 | character(len=*) :: s
| 1
Error: Entity with assumed character length at (1) must be a dummy argument or a PARAMETER
temp.f95:47:54:
47 | allocate(character(len=len(roman)+len(decode(n))) :: roman)
| 1
Error: Function ‘decode’ at (1) cannot be called recursively, as it is not RECURSIVE
temp.f95:43:39:
43 | allocate(character(len=len(decode(n / 1000))+1) :: roman)
| 1
Error: Function ‘decode’ at (1) cannot be called recursively, as it is not RECURSIVE
temp.f95:44:20:
44 | roman = decode(n / 1000) // M
| 1
Error: Function ‘decode’ at (1) cannot be called recursively, as it is not RECURSIVE
temp.f95:45:12:
45 | n = mod(n, 1000)
| 1
Error: Dummy argument ‘n’ with INTENT(IN) in variable definition context (assignment) at (1)
temp.f95:48:32:
48 | roman = roman // decode(n)
| 1
Error: Function ‘decode’ at (1) cannot be called recursively, as it is not RECURSIVE
PROGRAM ROMAN_TO_INTEGER
IMPLICIT NONE
CHARACTER(LEN=15) :: s
INTEGER :: i, j, value
! Read input
READ(*,*) s
! Initialize variables
i = 1
j = 1
value = 0
! Loop through the input string
DO WHILE (i <= LEN(s))
! Check for valid characters
IF (s(i:i) /= "I" .AND. s(i:i) /= "V" .AND. s(i:i) /= "X" .AND. &
s(i:i) /= "L" .AND. s(i:i) /= "C" .AND. s(i:i) /= "D" .AND. &
s(i:i) /= "M") THEN
PRINT *, "Invalid input"
STOP
END IF
! Check for subtraction
IF (s(i:i+1) == "IV" .OR. s(i:i+1) == "IX" .OR. s(i:i+1) == "XL" .OR. &
s(i:i+1) == "XC" .OR. s(i:i+1) == "CD" .OR. s(i:i+1) == "CM") THEN
value = value - (10 ** (j-1))
i = i + 2
j = j + 1
ELSE
! Check for addition
IF (s(i:i+1) == "II" .OR. s(i:i+1) == "XX" .OR. s(i:i+1) == "XXX" .OR. &
s(i:i+1) == "CCC" .OR. s(i:i+1) == "DDD" .OR. s(i:i+1) == "MMM") THEN
value = value + (10 ** (j-1))
i = i + 2
j = j + 1
ELSE
! Check for single digit
IF (s(i:i) == "I") THEN
value = value + 1
i = i + 1
j = j + 1
ELSE IF (s(i:i) == "V") THEN
value = value + 5
i = i + 1
j = j + 1
ELSE IF (s(i:i) == "X") THEN
value = value + 10
i = i + 1
j = j + 1
ELSE IF (s(i:i) == "L") THEN
value = value + 50
i = i + 1
j = j + 1
ELSE IF (s(i:i) == "C") THEN
value = value + 100
i = i + 1
j = j + 1
ELSE IF (s(i:i) == "D") THEN
value = value + 500
i = i + 1
j = j + 1
ELSE IF (s(i:i) == "M") THEN
value = value + 1000
i = i + 1
j = j + 1
END IF
END IF
END IF
END DO
! Print output
PRINT *, value
END PROGRAM ROMAN_TO_INTEGER
At line 9 of file temp.f95 (unit = 5, file = 'stdin') Fortran runtime error: End of file Error termination. Backtrace: #0 0x7e92e15dc960 in ??? #1 0x7e92e15dd4d9 in ??? #2 0x7e92e183117b in ??? #3 0x7e92e182a684 in ??? #4 0x7e92e182b2aa in ??? #5 0x5679b07db262 in MAIN__ #6 0x5679b07db864 in main
def roman_to_int(s):
roman_values = {'I': 1, 'V': 5, 'X': 10, 'L': 50, 'C': 100, 'D': 500, 'M': 1000}
total = 0
prev_value = 0
for c in s:
current_value = roman_values[c]
if current_value > prev_value:
total += current_value - 2 * prev_value
else:
total += current_value
prev_value = current_value
return total
The algorithm iterates through the input string, which represents the Roman numeral. At each iteration, the character is converted to its corresponding integer value using a hash map. Then, the value is added to the total. However, if the current value is greater than the previous value, it means that we need to subtract the previous value from the current value (while considering that the previous value has already been added once). To do this, we add to the total the current value minus 2 times the previous value. Finally, the previous value is updated, and the loop continues. After the loop finishes, the total gives us the integer value equivalent to the Roman numeral.
int romanToInt(string s) {
unordered_map<char, int> roman_values = { {'I', 1}, {'V', 5}, {'X', 10}, {'L', 50}, {'C', 100}, {'D', 500}, {'M', 1000} };
int total = 0;
int prev_value = 0;
for (char c : s) {
int current_value = roman_values[c];
if (current_value > prev_value)
total += current_value - (2 * prev_value);
else
total += current_value;
prev_value = current_value;
}
return total;
}
The algorithm iterates through the input string, which represents the Roman numeral. At each iteration, the character is converted to its corresponding integer value using a hash map. Then, the value is added to the total. However, if the current value is greater than the previous value, it means that we need to subtract the previous value from the current value (while considering that the previous value has already been added once). To do this, we add to the total the current value minus 2 times the previous value. Finally, the previous value is updated, and the loop continues. After the loop finishes, the total gives us the integer value equivalent to the Roman numeral.