0421for循环各类题目

Posted 2021-02-27 raising

for循环要点
1.确认外层控制内容
2.确认内层控制内容
3.将打印内容与行号产生关系式

/*

难度系数：重辣
     A
    ABA
   ABCBA
  ABCDCBA
 ABCDEDCBA
ABCDEFEDCBA
*/

class Demo8 {
	public static void main(String[] args) {
		
		char ch = ‘A‘;
		int line = 10;
				
		for (int i = 1; i <= line;i++) {

			ch = ‘A‘;
			
			//输出空格
			for (int j = 1; j <= line - i; j++) {
				System.out.print(" ");
			}
			
			int cn = 2 * i - 1;
			int bacCharNum = cn / 2;
			int froCharNum = cn - bacCharNum;
		
			//输出每行的前半部分
			for (int j = 1;j <= froCharNum ;j++) {
				System.out.print(ch);
				ch++;
			}
			
			//输出每行的后半部分
			ch -= 2;
			for (int j = 1;j <= bacCharNum ;j++) {
				System.out.print(ch);
				ch--;
			}			
			System.out.println();
		}
	}
}
/*
输出结果：

         A
        ABA
       ABCBA
      ABCDCBA
     ABCDEDCBA
    ABCDEFEDCBA
   ABCDEFGFEDCBA
  ABCDEFGHGFEDCBA
 ABCDEFGHIHGFEDCBA
ABCDEFGHIJIHGFEDCBA
*/