计算力扣银行的钱

/*
 * Solution in Java using Streams
 * The problem requires calculating the total amount saved in the bank after n days.
 * The amount saved follows a pattern where each day of the week the saving increases by 1 starting from 1 on Monday.
 * Each subsequent Monday the starting amount increases by 1.
 * For example, if n = 10, the savings would be 1, 2, 3, 4, 5, 6, 7, 2, 3, 4.
 */

import java.util.stream.IntStream;

public class SavingsCalculatorStream {
    public int totalSavings(int n) {
        return IntStream.rangeClosed(1, n)
                        .map(i -> ((i - 1) / 7) + 1 + ((i - 1) % 7))
                        .sum();
    }
    
    public static void main(String[] args) {
        SavingsCalculatorStream scs = new SavingsCalculatorStream();
        System.out.println(scs.totalSavings(4));  // Output: 10
        System.out.println(scs.totalSavings(10)); // Output: 37
        System.out.println(scs.totalSavings(20)); // Output: 96
    }
}