生兔子问题：
package com.atguigu.exer;
import java.util.Scanner;
public class Fibonacci {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("Please input n:");
int n = scanner.nextInt();
System.out.println("当前值为" + fibonacci(n));
int sum = 0;
for(int i = 1; i <= n; i++){
sum += fibonacci(n);
}
System.out.println(sum);
}
public static int fibonacci(int n){
if(n < 2){
return 1;
}else {
return fibonacci(n-1) +fibonacci(n-2);
}
}
}
统计字符个数：
package com.atguigu.exer;
public class total {
public static void main(String[] args){
String s = "aasddsfdg213SS";
int countNum = 0;
int countUpper = 0;
int countLower = 0;
int countOther = 0;
for(int i = 0; i < s.length(); i ++){
char c = s.charAt(i);
if (c >= 'A' && c <= 'Z') {
countUpper++;
}else if (c >= 'a' && c <= 'z') {
countLower++;
}else if (c >= '0' && c <= '9') {
countNum++;
}else {
countOther++;
}
}
System.out.println(countLower);
System.out.println(countUpper);
System.out.println(countNum);
System.out.println(countOther);
}
}
