Description
Given a string formula representing a chemical formula, return the count of each atom in alphabetical order.
Examples
Input:
formula = "H2O"Output:
"H2O"Explanation:
Parse: H appears 2x, O appears 1x. Output alphabetically: H2O. No parentheses to expand.
Input:
Ca(NO3)2Output:
"CaN2O6"Explanation:
Ca:1, then (NO3)x2 = N:2, O:6. Alphabetically: CaN2O6.
Input:
Al2(SO4)3Output:
"Al2O12S3"Explanation:
Al:2, then (SO4)x3 = S:3, O:12. Alphabetically: Al2O12S3.
Constraints
- •
1 ≤ formula.length ≤ 1000 - •
formula consists of letters, digits, '(', ')'.