Electricity Tier
Programming Basics · C#
TASK
Problem
Given integer electricity usage, charge 2 per unit for the first 100 units and 3 per unit for usage above 100; print the total cost. Print only the required answer; do not print prompts, labels, or debug text.
EXAMPLE
Example
50
100
LIMITS
Constraints
- Every token parsed with `int.Parse` is a valid 32-bit signed integer; test data avoid unintended overflow in the task's intended calculation. - Input is syntactically valid for the task except where invalid input is deliberately being tested (for example a `TryParse`/validation exercise). - Print only the required answer; do not add prompts, labels, debug text, or extra spaces/lines.
LEARN
Theory for this problem
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Piecewise formulas are best expressed as clear, exhaustive branches. Check branch boundaries carefully so every input follows exactly one intended rule. For **Electricity Tier**, the concrete requirement is: Given integer electricity usage, charge 2 per unit for the first 100 units and 3 per unit for usage above 100; print the total cost. Keep input parsing, the core operation, and output formatting separate so each part can be checked independently. Before coding, trace the first example by hand and identify the smallest valid or boundary-shaped input; this exposes off-by-one, sign, empty/single-element, and formatting mistakes before they reach the implementation.
NEED HELP?
Hints
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['Piecewise formulas are best expressed as clear, exhaustive branches. Check branch boundaries carefully so every input follows exactly one intended rule.', 'Before coding, state this exact input-to-output rule: Given integer electricity usage, charge 2 per unit for the first 100 units and 3 per unit for usage above 100; print the total cost.', 'Trace the public example by hand, then test the smallest input and the edge case most likely to change an index, branch, tie, or empty result.']
ANSWER
Solution
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using System;
class Program
{
static void Main()
{
int usage=int.Parse(Console.ReadLine());
int result=usage<=100?usage*2:200+(usage-100)*3;
Console.WriteLine(result);
}
}