Given a String of date of format YYYYMMDD, our task is to compute the life path number. Life Path Number is the number obtained by summation of individual digits of each element repeatedly till single digit, of datestring. Used in Numerology Predictions.
Examples:
Input : test_str = “19970314”
Output : 7
Explanation : 1 + 9 + 9 + 7 = 26 , 2 + 6 = 8 [ year ] ; 0 + 3 = 3 [ month ] ; 1 + 4 = 5 [ day ]. 5 + 3 + 8 = 16 ; 1 + 6 = 7.
Input : test_str = “19970104”
Output : 4
Explanation : 1 + 9 + 9 + 7 = 26 , 2 + 6 = 8 [ year ] ; 0 + 1 = 1 [ month ] ; 0 + 4 = 4 [ day ]. 4 + 1 + 8 = 13 ; 1 + 3 = 4.
Method 1: Using loop
The logic behind computing this is getting a summation of each digit and perform %10 at each step. This way result curlers to single digit if it goes to double-digit.
Python3
# Python3 code to demonstrate working of# Life Path Number# Using loop# initializing stringtest_str = "19970314"# printing original stringprint("The original string is : " + str(test_str))res = 0for num in test_str: res += int(num) # modulation in case of 2 digit number if res > 9: res = res % 10 + res // 10# printing resultprint("Life Path Number : " + str(res)) |
Output:
The original string is : 19970314 Life Path Number : 7
Time Complexity: O(n)
Space Complexity: O(n)
Method 2: Using recursion
Similar way as above, the difference being the recursive function is used for repeated modulation in case of digit count greater than 1.
Python3
# Python3 code to demonstrate working of# Life Path Number# Using recursion# initializing stringtest_str = "19970314"# printing original stringprint("The original string is : " + str(test_str))# recursion function definitiondef lpn(num): return num if num < 10 else lpn(num // 10 + num % 10)# recursive function initial callres = lpn(int(test_str))# printing resultprint("Life Path Number : " + str(res)) |
Output:
The original string is : 19970314 Life Path Number : 7
Time Complexity: O(n)
Auxiliary Space: O(n)
Method 3: Using reduce()
This method uses reduce function from functools module to perform the computation in a single line code.
Python3
# Python3 code to demonstrate working of# Life Path Number# Using reduce() # importing functools modulefrom functools import reduce # initializing stringtest_str = "19970314" # printing original stringprint("The original string is : " + str(test_str)) # using reduce to compute sumres = reduce(lambda x, y : x + int(y), test_str, 0) # using recursive functionwhile res > 9: res = reduce(lambda x, y : x + int(y), str(res), 0) # printing resultprint("Life Path Number : " + str(res)) |
The original string is : 19970314 Life Path Number : 7
Time Complexity: O(n)
Auxiliary Space: O(1)
Method 4: Using mathematical formulas
Step-by-Step approach:
Initialize the input string test_str as “19970314”
Compute the sum of all the digits of the string by using the following formula:
sum = (int(test_str[0]) + int(test_str[1]) + int(test_str[2]) + int(test_str[3]) + int(test_str[4]) + int(test_str[5]) + int(test_str[6]) + int(test_str[7]))
Repeat step 2 until the sum obtained is less than or equal to 9.
Return the sum obtained as the Life Path Number.
Python3
# Python3 code to demonstrate working of# Life Path Number# Using mathematical formulas# initializing stringtest_str = "19970314"# printing original stringprint("The original string is : " + str(test_str))# using mathematical formulaswhile len(test_str) > 1: sum = 0 for digit in test_str: sum += int(digit) test_str = str(sum)# printing resultprint("Life Path Number : " + str(test_str)) |
The original string is : 19970314 Life Path Number : 7
Time Complexity: O(n)
Auxiliary Space: O(1)
