Java計算1-100的和(要求盡量考慮代碼優化)

 

1.遞歸算法

    public static void main(String[] args) {
        System.out.println(add(1));
    }

    private static int add(int i) {
        if (i < 100 && i > 0) {
            return i + add(i + 1);
        }
        else {
            return i;
        }
    }

 

2..for循環

    public static void main(String[] args) {
        int sum = 0;
        for (int i = 1; i <= 100; i++) {
            sum += i;
        }
        System.out.println("1到100累加的和為：" + sum);
    }

3.while循環

    public static void main(String[] args) {
        int sum = 0;
        int i = 1;
        while (i <= 100) {
            sum += i;
            i++;
        }
        System.out.println("1到100累加的和為：" + sum);
    }

4.do.....while循環

    public static void main(String[] args) {
        int sum = 0;
        int i = 1;
        do {
            sum += i;
            i++;
        } while (i <= 100);
        System.out.println("1到100累加的和為：" + sum);
    }