数字三角形的显示 java

实现一行符号的输出

public class line {
    public static void main(String[] args) {

        // 实现输出一行符号的功能
        int start_num = 2;  // 符号数量

        for (int num = 1; num <= start_num; num++) {
            System.out.print("*");
        }
    }
}

效果

"C:\Program Files\Java\jdk1.7.0_17\bin\java.exe" "-javaagent:D:\Program Files\JetBrains\IntelliJ IDEA Educational Edition 2020.2\lib\idea_rt.jar=32825:D:\Program Files\JetBrains\IntelliJ IDEA Educational Edition 2020.2\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.7.0_17\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jce.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jfxrt.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\resources.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\rt.jar;C:\Users\Administrator\IdeaProjects\untitled\out\production\untitled" line
**
Process finished with exit code 0

实现直角三角形的输出 1 3 5

public class sanzhi {
    public static void main(String[] args) {
        // 输出一个直角三角形
        // 1行1符号，2行3符号，3行5符号

        // 输出数据
        int line_num = 6;   // 行数
        for (int row = 0; row < line_num; row++) {
            // 根据row算出应显示的符号数量
            int char_num = 1 + 2 * row;

            // char num 是多少，就会输出多少个符号
            for (int num = 1; num <= char_num; num++) {
                System.out.print("*");
            }
            System.out.println();


        }
    }
}

效果

"C:\Program Files\Java\jdk1.7.0_17\bin\java.exe" "-javaagent:D:\Program Files\JetBrains\IntelliJ IDEA Educational Edition 2020.2\lib\idea_rt.jar=32834:D:\Program Files\JetBrains\IntelliJ IDEA Educational Edition 2020.2\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.7.0_17\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jce.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jfxrt.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\resources.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\rt.jar;C:\Users\Administrator\IdeaProjects\untitled\out\production\untitled" sanzhi
*
***
*****
*******
*********
***********

Process finished with exit code 0

实现等腰三角形的输出

代码

public class sanzhi {
    public static void main(String[] args) {

        // 为了优化性能，把常用的变量声明在这里
        int char_num;
        int row_num;
        int space_num;

        // 输出数据
        int line_num = 6;   // 行数
        for (int row_idx = 0; row_idx < line_num; row_idx++) {

            // 根据row算出应显示的符号数量
            char_num = 1 + 2 * row_idx;
            row_num = row_idx + 1;
            space_num = line_num - row_num;

            // 输出空格
            for (int sn = 0; sn < space_num; sn++) {
                System.out.print(" ");
            }


            // 输出符号
            // char num 是多少，就会输出多少个符号
            for (int num = 1; num <= char_num; num++) {
                System.out.print("*");
            }
            System.out.println();


        }
    }
}

效果

"C:\Program Files\Java\jdk1.7.0_17\bin\java.exe" "-javaagent:D:\Program Files\JetBrains\IntelliJ IDEA Educational Edition 2020.2\lib\idea_rt.jar=32999:D:\Program Files\JetBrains\IntelliJ IDEA Educational Edition 2020.2\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.7.0_17\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jce.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jfxrt.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\resources.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\rt.jar;C:\Users\Administrator\IdeaProjects\untitled\out\production\untitled" sanzhi
     *
    ***
   *****
  *******
 *********
***********

Process finished with exit code 0

数字功能的实现

public class testnum {
    public static void main(String[] args) {
        // 生成特别的数据
        int mid_num = 5;

        for (int t = 1; t <= mid_num; t++) {
            // t = 1,2,3
            System.out.print(t);
        }
        for (int f = mid_num - 1; f > 0; f--) {
            System.out.print(f);
        }
    }
}

效果

"C:\Program Files\Java\jdk1.7.0_17\bin\java.exe" "-javaagent:D:\Program Files\JetBrains\IntelliJ IDEA Educational Edition 2020.2\lib\idea_rt.jar=33172:D:\Program Files\JetBrains\IntelliJ IDEA Educational Edition 2020.2\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.7.0_17\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jce.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jfxrt.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\resources.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\rt.jar;C:\Users\Administrator\IdeaProjects\untitled\out\production\untitled" testnum
123454321
Process finished with exit code 0

最终完成

public class sanzhi {
    public static void main(String[] args) {

        // 为了优化性能，把常用的变量声明在这里
        int char_num;
        int row_num;
        int space_num;

        // 输出数据
        int line_num = 9;   // 行数
        for (int row_idx = 0; row_idx < line_num; row_idx++) {

            // 根据row算出应显示的符号数量
            char_num = 1 + 2 * row_idx;
            row_num = row_idx + 1;  // 行号
            space_num = line_num - row_num;

            // 输出空格
            for (int sn = 0; sn < space_num; sn++) {
                System.out.print(" ");
            }

            // 输出符号，符号与行号相关联
            int mid_num = row_num;  // 最中间的数与行号是一样的

            for (int t = 1; t <= mid_num; t++) {
                // t = 1,2,3
                System.out.print(t);
            }
            for (int f = mid_num - 1; f > 0; f--) {
                System.out.print(f);
            }

            System.out.println();


        }
    }
}

效果

"C:\Program Files\Java\jdk1.7.0_17\bin\java.exe" "-javaagent:D:\Program Files\JetBrains\IntelliJ IDEA Educational Edition 2020.2\lib\idea_rt.jar=33178:D:\Program Files\JetBrains\IntelliJ IDEA Educational Edition 2020.2\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.7.0_17\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jce.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jfxrt.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\resources.jar;C:\Program Files\Java\jdk1.7.0_17\jre\lib\rt.jar;C:\Users\Administrator\IdeaProjects\untitled\out\production\untitled" sanzhi
        1
       121
      12321
     1234321
    123454321
   12345654321
  1234567654321
 123456787654321
12345678987654321

Process finished with exit code 0