char類型打印圖形需要注意的地方

錯誤代碼展示：

import java.util.List;
import java.util.ArrayList;
import java.util.Scanner;

public class Main3 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		while (n-- > 0) {
			int hang = sc.nextInt();
			int ge = sc.nextInt();
			char[][] chars = new char[hang][hang];
			int k = hang / 2 + 1;
			chars[k - 1][k - 1] = 'X';
			for (int i = k - 2; i >= 0; i--) {
				for (int j = 0; j < chars[0].length; j++) {
					if (j < hang / 2) {
						if (chars[i + 1][j + 1] == 'X') {
							chars[i][j] = 'X';
						} else {
							chars[i][j] = ' ';
						}
					} else if (j > hang / 2) {
						if (chars[i + 1][j - 1] == 'X') {
							chars[i][j] = 'X';
						} else {
							chars[i][j] = ' ';
						}
					}
				}
			}
			for (int i = k; i < chars.length; i++) {
				for (int j = 0; j < chars[0].length; j++) {
					if (j < hang / 2) {
						if (chars[i - 1][j + 1] == 'X') {
							chars[i][j] = 'X';
						} else {
							chars[i][j] = ' ';
						}
					} else if (j > hang / 2) {
						if (chars[i - 1][j - 1] == 'X') {
							chars[i][j] = 'X';
						} else {
							chars[i][j] = ' ';
						}
					}
				}
			}
			int kk = 0;
			int jj = 0;
			for (int i = 0; i < ge; i++) {
				if (i == 0) {
					kk = 0;
				} else {
					kk = 1;
				}
				for (int j = kk; j < chars.length; j++) {
					for (int j2 = 0; j2 < chars[0].length; j2++) {
						if (j == hang / 2) {
							if (chars[j][j2] == 'X') {
								System.out.print(chars[j][j2]);
								break;
							} else {
								System.out.print(chars[j][j2]);
							}
						} else {
							if (chars[j][j2] == 'X') {
								jj++;
							}
							System.out.print(chars[j][j2]);
							if (jj == 2) {
								break;
							}
						}
					}
					jj = 0;
					System.out.println();
				}
			}
		if(n!=0) {
			System.out.println();
		}
		}
	}
}

錯誤分析：

此題採用的是char型的二維數組打印圖形，在此要記住，用char型數組打印圖形一定要先初始化!!!

原因：

正確代碼展示：

import java.util.List;
import java.util.ArrayList;
import java.util.Scanner;

public class Main3 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		while (n-- > 0) {
			int hang = sc.nextInt();
			int ge = sc.nextInt();
			char[][] chars = new char[hang][hang];
			for (int i = 0; i < chars.length; i++) {
				for (int j = 0; j < chars[0].length; j++) {
					chars[i][j]=' ';
				}
			}
			int k = hang / 2 + 1;
			chars[k - 1][k - 1] = 'X';
			for (int i = k - 2; i >= 0; i--) {
				for (int j = 0; j < chars[0].length; j++) {
					if (j < hang / 2) {
						if (chars[i + 1][j + 1] == 'X') {
							chars[i][j] = 'X';
						} else {
							chars[i][j] = ' ';
						}
					} else if (j > hang / 2) {
						if (chars[i + 1][j - 1] == 'X') {
							chars[i][j] = 'X';
						} else {
							chars[i][j] = ' ';
						}
					}
				}
			}
			for (int i = k; i < chars.length; i++) {
				for (int j = 0; j < chars[0].length; j++) {
					if (j < hang / 2) {
						if (chars[i - 1][j + 1] == 'X') {
							chars[i][j] = 'X';
						} else {
							chars[i][j] = ' ';
						}
					} else if (j > hang / 2) {
						if (chars[i - 1][j - 1] == 'X') {
							chars[i][j] = 'X';
						} else {
							chars[i][j] = ' ';
						}
					}
				}
			}
			int kk = 0;
			int jj = 0;
			for (int i = 0; i < ge; i++) {
				if (i == 0) {
					kk = 0;
				} else {
					kk = 1;
				}
				for (int j = kk; j < chars.length; j++) {
					for (int j2 = 0; j2 < chars[0].length; j2++) {
						if (j == hang / 2) {
							if (chars[j][j2] == 'X') {
								System.out.print(chars[j][j2]);
								break;
							} else {
								System.out.print(chars[j][j2]);
							}
						} else {
							if (chars[j][j2] == 'X') {
								jj++;
							}
							System.out.print(chars[j][j2]);
							if (jj == 2) {
								break;
							}
						}
					}
					jj = 0;
					System.out.println();
				}
			}
		if(n!=0) {
			System.out.println();
		}
		}
	}
}