1 
public void floodFill(int x, int y) {
    if (x >= 0 && x <= 9 && y >= 0 && y <= 9) {
        if (mines[x][y] == 0) {
            btn[x][y].setBackground(Color.GRAY);
            floodFill(x - 1, y);
            // floodFill(x + 1, y);
            floodFill(x, y - 1);
            // floodFill(x, y + 1);
        } else {
            return;
        }
    }
}

これは、私が作成している掃海艇のようなゲームに使用している floodFill コードです。ただし、ご覧のとおり、2 つの部分がコメント アウトされています。コメントを外してプログラムを実行するとすぐに。

Exception in thread "AWT-EventQueue-0" java.lang.StackOverflowError
at sun.awt.NullComponentPeer.setBackground(Unknown Source)
at java.awt.Component.setBackground(Unknown Source)
at javax.swing.JComponent.setBackground(Unknown Source)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:95)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:99)
at Minesweeper.BoardBuild.floodFill(BoardBuild.java:98)

なぜこれが起こっているのかわからず、修正方法もわかりません。どんな助けでも大歓迎です。

編集：

他の誰かがこの問題に遭遇した場合に備えて、Fls'Zen がチャットで思いついた答え

public void floodFill(int x, int y) {
    if (x >= 0 && x <= 9 && y >= 0 && y <= 9) {
        if (mines[x][y] == 0 && btn[x][y].getBackground() != Color.GRAY) {
            btn[x][y].setBackground(Color.GRAY);
            floodFill(x - 1, y);
            floodFill(x + 1, y);
            floodFill(x, y - 1);
            floodFill(x, y + 1);
        } else {
            return;
        }
    }
}
4

2 に答える 2

4

これらの行のコメントを外したら、 と の両方に対して floodFill を呼び出しx - 1ますx + 1。に対して floodFill を呼び出すとどうなるかを考えてみましょうx - 1。また、floodFill を呼び出しx + 1たx値である floodFill も呼び出します。x同じ 2 つの値、元のx値、および元の値に対して自分自身を呼び出す floodFill がありx - 1ます。

再帰を使用する場合は、1 つの「方向」(+ または -) を選択して、それを使用する必要があります。それ以外の場合は、評価された座標を追跡するために何かを追加する必要があります。

編集: 次のコードは、セルがアルゴリズムによって既に処理されている場合に再帰を回避します。これは、現在の座標の背景色をチェックすることによって実現されます。背景が既に灰色の場合、座標は既に処理されていると見なされ、再度処理されることはありません。

if (mines[x][y] == 0 && btn[x][y].getBackground() != Color.GRAY) {
    btn[x][y].setBackground(Color.GRAY);
    floodFill(x - 1, y);
    floodFill(x + 1, y);
    floodFill(x, y - 1);
    floodFill(x, y + 1);
} else {
    return;
}
于 2012-12-29T00:35:15.433 に答える
0

すでにチェックしたマスを記録していないように見えるため、ボード全体を無限にループしています。

于 2012-12-29T00:34:09.227 に答える