Celsius to Fahrenheit

Problem

Convert a temperature in degrees Celsius to degrees Fahrenheit using F = C × 9 / 5 + 32.

Implement celsius_to_fahrenheit(celsius).

celsius: The temperature in degrees Celsius.

Return the temperature in degrees Fahrenheit (a decimal number).

-273.15 ≤ celsius ≤ 10,000

Example 1

Input:
celsius = 100.0

Expected output:
expected = 212.0

Input:
double celsius = 100.0;

Expected output:
double expected = 212.0;

Input:
double celsius = 100.0;

Expected output:
double expected = 212.0;

100 × 9 / 5 + 32 = 212, the boiling point of water.

Example 2

Input:
celsius = -40.0

Expected output:
expected = -40.0

Input:
double celsius = -40.0;

Expected output:
double expected = -40.0;

Input:
double celsius = -40.0;

Expected output:
double expected = -40.0;

-40 × 9 / 5 + 32 = -40: both scales meet at -40.

Try on your own first, then open one hint at a time.

Hint 1

This is a direct unit conversion from one linear scale to another.

Hint 2

Apply the given formula carefully, especially the order of multiplication and division.

Hint 3

Keep the result as a decimal value, since many inputs do not convert to integers exactly.

Expected complexity

O(1) time, O(1) extra space

This challenge is adapted for CodeUtility. Follow the statement and constraints above.