Java 多維數組應用實戰：圖形繪製與螺旋矩陣生成算法

6.6 多維數組使用示例：數據驅動邏輯的兩大經典場景

6.6.3 存儲圖形結構：數組作為渲染數據源

需求：根據二維數組值繪製圖形，0→空格，1→星號(*)

int[][] map = {
    {0,0,0,1,0,0,0},
    {0,0,1,0,1,0,0},
    {0,1,0,0,0,1,0},
    {1,0,0,0,0,0,1},
    {0,1,0,0,0,1,0},
    {0,0,1,0,1,0,0},
    {0,0,0,1,0,0,0}
};

實現代碼

for (int row = 0; row < map.length; row++) {
    for (int col = 0; col < map[row].length; col++) {
        switch (map[row][col]) {
            case 0: System.out.print(' '); break;
            case 1: System.out.print('*'); break;
        }
    }
    System.out.println();  // 換行
}

應用場景：遊戲地圖數據、俄羅斯方塊塊狀數據、像素圖渲染。體現**數據與邏輯分離**設計思想。

6.6.4 螺旋數組：邊界轉向算法經典實現

需求：生成 n×m 螺旋數組，數值從 1 遞增，順時針旋轉填充

4×4:          4×5:
1  2  3  4    1  2  3  4  5
12 13 14 5    14 15 16 17 6
11 16 15 6    13 20 19 18 7
10  9  8 7    12 11 10  9  8

核心算法：狀態機 + 邊界檢測

int n = 4, m = 5;
int[][] data = new int[n][m];
int dire = 3;  // 0上 1下 2左 3右
final int UP=0, DOWN=1, LEFT=2, RIGHT=3;
int value = 1, row = 0, col = 0;
data[0][0] = 1;

while (value < n * m) {
    switch (dire) {
        case UP:    row--; if (row<0 || data[row][col]!=0) { row++; dire=RIGHT; continue; } break;
        case DOWN:  row++; if (row>=n || data[row][col]!=0) { row--; dire=LEFT; continue; } break;
        case LEFT:  col--; if (col<0 || data[row][col]!=0) { col++; dire=UP; continue; } break;
        case RIGHT: col++; if (col>=m || data[row][col]!=0) { col--; dire=DOWN; continue; } break;
    }
    value++;
    data[row][col] = value;
}

// 輸出右對齊
for (int i=0; i