namespace IVSR.Designpattern.Strategy {
    //The interface for the strategies
    public interface ICalculate {
       int Calculate(int value1, int value2);
    }

    //strategies
    //Strategy 1: Minus
    class Minus : ICalculate {
        public int Calculate(int value1, int value2) {
            return value1 - value2;
        }
    }

    //Strategy 2: Plus
    class Plus : ICalculate {
        public int Calculate(int value1, int value2) {
            return value1 + value2;
        }
    }

    //The client
    class CalculateClient {
        private ICalculate calculateStrategy;

        //Constructor: assigns strategy to interface
        public CalculateClient(ICalculate strategy) {
            this.calculateStrategy = strategy;
        }

        //Executes the strategy
        public int Calculate(int value1, int value2) {
            return calculateStrategy.Calculate(value1, value2);
        }
    }

    //Initialize
    protected void Page_Load(object sender, EventArgs e) {
        CalculateClient minusClient = new CalculateClient(new Minus());
        Response.Write("
Minus: " + minusClient.Calculate(7, 1).ToString());

        CalculateClient plusClient = new CalculateClient(new Plus());
        Response.Write("
Plus: " + plusClient.Calculate(7, 1).ToString());
    }
}