刷题DAY21

字符逆转

题目：将一个字符串str的内容颠倒过来，并输出。str的长度不超过100个字符

输入：输入包括一行。第一行输入的字符串

输出：输出转换好的逆序字符串

输入：I am a student

输出：tneduts a ma I

import java.util.Scanner;
public class 字符逆转 {public static void main(String[] args) {Scanner sc=new Scanner(System.in);String st = sc.nextLine();char c[] = new char[st.length()];for (int i = 0; i < c.length; i++) {c[i]=st.charAt(i);}for (int i = c.length-1; i>= 0; i--) {System.out.print(c[i]);}}}
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import java.util.Scanner;
public class 字符逆转 {public static void main(String[] args) {Scanner sc = new Scanner(System.in);String str = sc.nextLine();StringBuffer stb = new StringBuffer(str);StringBuffer reverse = stb.reverse();System.out.println(reverse.toString());}
}
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打印金字塔

题目：输入n值，打印下列形状的金字塔，其中n代表金字塔的层数。

输入：输入只有一个正整数n(1<=n<=9)

输出：打印金字塔图形，其中每个数字之间有一个空格

输入：3

输出：

1 1 2 1 1 2 3 2 1

import java.util.Scanner;
public class 打印金字塔 {public static void main(String[] args) {// TODO Auto-generated method stubScanner reader = new Scanner(System.in);int i, n, j;n = reader.nextInt();for (j = 1; j <= n; j++) {for (i = 1; i <= (n - j) * 2; i++) {System.out.print(" ");}for (i = 1; i <= j; i++) {System.out.print(i);if (i != j) {System.out.print(" ");}}for (i = j - 1; i >= 1; i--) {System.out.print(" " + i);}if (j != n)System.out.println();}}
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}
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