Java while语句练习 C语言的函数递归

1.

/* public static void main(String[] args) {
     int[] arr = {25, 24, 12, 98, 36, 45};
     int max = arr[0];//不能写0
     for (int i = 1; i < arr.length; i++) {
         if (arr[i] > max) {
             max = arr[i];
         }
     }
         System.out.println(max);
     }*/
 /*public static void main(String[] args) {
     double height=8844330;
     double paper=0.1;
     int num=0;
     while (paper<=height){
         paper=paper*2;
         num++;
     }
     System.out.println(num);
 }*/
 //求倒过来的数，若为回数，则为true
 /*public static void main(String[] args) {
     int number=9875;
     int temp=number;//记录一开始的输入值
     int num=0;
     while (number!=0){
         int ge=number%10;
         number=number/10;
         num =num*10+ge;
     }
     System.out.println(num);
     System.out.println(num==temp);
 }*/
 //只能用+-，算出商和余数
 /*public static void main(String[] args) {
     int a=9999999;
     int b=4;
     int num=0;
     while (a>=b){
         a=a-b;
         num++;
     }
     System.out.println("商为"+num);
     System.out.println("余数为"+a);
 }*/
 //do while语句 先执行，后判断

2.

#include<stdio.h>
int fac(int n);
int main(void)
{
    int m = 0;
    printf("请输入m的值：");
    scanf_s("%d", &m);
    printf("%d\n", fac(m));
    return 0;
}
int fac(int n)
{
    if (n < 1)
        return -1;
    else if (n == 1)
        return 1;
    else
    return n+fac(n-1);//一直循环fac()函数，直到n==1
}