我正在使用递归算法编写游戏，但编译时遇到“StackOverFlow错误”。我知道这可能是由于没有一个好的结束条款而且它会永远重新诅咒。我只想尝试如何解决它。 我也知道我要发布的代码有点太多但我想提供尽可能多的信息。有任何疑问，请问。
它从以下调用开始：
<cfpdfform action="populate" source="test.pdf" destination="GeneratedPDFs/test.pdf" overwrite="yes">
<cfpdfformparam name="FirstLine1" value="#Variables.FirstLine#">
<cfpdfformparam name="SecondLine1" value="#Variables.SecondLine#">
<cfpdfformparam name="AddressBox1" value="#Variables.AddressBox#">
<cfpdfformparam name="Body1" value="#Variables.Body1#">
<cfpdfformparam name="FirstLine2" value="#Variables.FirstLine#">
<cfpdfformparam name="SecondLine2" value="#Variables.SecondLine#">
<cfpdfformparam name="AddressBox2" value="#Variables.AddressBox#">
<cfpdfformparam name="Body2" value="#Variables.Body2#">
</cfpdfform>
<cfpdf action="write" source="GeneratedPostCards/!PostCard2013-Vipre.pdf" destination="GeneratedPostCards/!PostCard2013-Vipre-flat.pdf" flatten="yes" overwrite="true">
</cfpdf>
“solver2”方法和辅助方法如下：
Integer matrix[][] = new Integer[5][5];
Deque<String> path = new ArrayDeque<>();
ArrayList<Deque<String>> paths = new ArrayList<>();
CoordenateList cList = new CoordenateList();
solver2(matrix, 0, 0, 1, path, paths, cList);
其他类（Coordenate，CoordenateList）如下：
public static void solver2(Integer[][] matrix, int x, int y, int num,
Deque<String> path, ArrayList<Deque<String>> paths, CoordenateList cList) {
if (cList.getCoordenateByKey(Integer.toString(y) + "," + Integer.toString(x)) == null) {
Coordenate c = new Coordenate((Integer.toString(y) + "," + Integer.toString(x))); //substitir nos IF's
cList.addCoordenate(c);
}
if (y - 3 < 0 || (cList.getCoordenateByKey(Integer.toString(y) + "," + Integer.toString(x)).getVisited())[0] == true || matrix[y - 3][x] != null) {
//NORTE
if (x + 3 > matrix.length - 1 || (cList.getCoordenateByKey(Integer.toString(y) + "," + Integer.toString(x)).getVisited())[1] == true || matrix[y][x + 3] != null) {
//ESTE
if (y + 3 > matrix.length - 1 || (cList.getCoordenateByKey(Integer.toString(y) + "," + Integer.toString(x)).getVisited())[2] == true || matrix[y + 3][x] != null) {
//SUL
if (x - 3 < 0 || (cList.getCoordenateByKey(Integer.toString(y) + "," + Integer.toString(x)).getVisited())[3] == true || matrix[y][x - 3] != null) {
//OESTE
if (y - 2 < 0 || x + 2 > matrix.length - 1 || (cList.getCoordenateByKey(Integer.toString(y) + "," + Integer.toString(x)).getVisited())[4] == true || matrix[y - 2][x + 2] != null) {
//NE
if (y + 2 > matrix.length - 1 || x + 2 > matrix.length - 1 || (cList.getCoordenateByKey(Integer.toString(y) + "," + Integer.toString(x)).getVisited())[5] == true || matrix[y + 2][x + 2] != null) {
//SE
if (y + 2 > matrix.length - 1 || x - 2 < 0 || (cList.getCoordenateByKey(Integer.toString(y) + "," + Integer.toString(x)).getVisited())[6] == true || matrix[y + 2][x - 2] != null) {
//SO
if (y - 2 < 0 || x - 2 < 0 || (cList.getCoordenateByKey(Integer.toString(y) + "," + Integer.toString(x)).getVisited())[7] == true || matrix[y - 2][x - 2] != null) {
//NO
if (num == matrix.length * matrix.length) {
Deque<String> aux = new ArrayDeque<>();
aux.addAll(path);
paths.add(aux);
path.pop();
cleanRecord(num, matrix, cList); //desnecessário
num--;
} else {
//LOSER
path.pop();
num--;
y = getCoordenatePrevious(num, matrix)[1];
x = getCoordenatePrevious(num, matrix)[0];
num++;
cleanRecord(num, matrix, cList);
num--;
}
} else {
matrix[y - 2][x - 2] = num + 1;
(cList.getCoordenateByKey(Integer.toString(y) + "," + Integer.toString(x)).getVisited())[7] = true;
path.push(Integer.toString(y + 2) + "," + Integer.toString(x - 2));
solver2(matrix, x - 2, y + 2, num + 1, path, paths, cList);
}
} else {
matrix[y + 2][x - 2] = num + 1;
(cList.getCoordenateByKey(Integer.toString(y) + "," + Integer.toString(x)).getVisited())[6] = true;
path.push(Integer.toString(y + 2) + "," + Integer.toString(x - 2));
solver2(matrix, x - 2, y + 2, num + 1, path, paths, cList);
}
} else {
matrix[y + 2][x + 2] = num + 1;
(cList.getCoordenateByKey(Integer.toString(y) + "," + Integer.toString(x)).getVisited())[5] = true;
path.push(Integer.toString(y + 2) + "," + Integer.toString(x + 2));
solver2(matrix, x + 2, y + 2, num + 1, path, paths, cList);
}
} else {
matrix[y - 2][x + 2] = num + 1;
(cList.getCoordenateByKey(Integer.toString(y) + "," + Integer.toString(x)).getVisited())[4] = true;
path.push(Integer.toString(y - 2) + "," + Integer.toString(x + 2));
solver2(matrix, x + 2, y - 2, num + 1, path, paths, cList);
}
} else {
matrix[y][x - 3] = num + 1;
(cList.getCoordenateByKey(Integer.toString(y) + "," + Integer.toString(x)).getVisited())[3] = true;
path.push(Integer.toString(y) + "," + Integer.toString(x - 3));
solver2(matrix, x - 3, y, num + 1, path, paths, cList);
}
} else {
matrix[y + 3][x] = num + 1;
(cList.getCoordenateByKey(Integer.toString(y) + "," + Integer.toString(x)).getVisited())[2] = true;
path.push(Integer.toString(y + 3) + "," + Integer.toString(x));
solver2(matrix, x, y + 3, num + 1, path, paths, cList);
}
} else {
matrix[y][x + 3] = num + 1;
(cList.getCoordenateByKey(Integer.toString(y) + "," + Integer.toString(x)).getVisited())[1] = true;
path.push(Integer.toString(y) + "," + Integer.toString(x + 3));
solver2(matrix, x + 3, y, num + 1, path, paths, cList);
}
} else {
matrix[y - 3][x] = num + 1;
(cList.getCoordenateByKey(Integer.toString(y) + "," + Integer.toString(x)).getVisited())[0] = true;
path.push(Integer.toString(y - 3) + "," + Integer.toString(x));
solver2(matrix, x, y - 3, num + 1, path, paths, cList);
}
int cont = 0;
if (checkIfNumExists(num, matrix)) {
boolean[] b = cList.getCoordenateByKey(Integer.toString(getCoordenatePrevious(num, matrix)[1]) + "," + Integer.toString(getCoordenatePrevious(num, matrix)[0])).getVisited();
if (y - 3 >= 0 && matrix[y - 3][x] == null && b[0] == false) {
//NORTE
cont++;
solver2(matrix, x, y, num, path, paths, cList);
} else if (x + 3 < matrix.length && matrix[y][x + 3] == null && b[1] == false) {
//ESTE
cont++;
solver2(matrix, x, y, num, path, paths, cList);
} else if (y + 3 < matrix.length && matrix[y + 3][x] == null && b[2] == false) {
//SUL
cont++;
solver2(matrix, x, y, num, path, paths, cList);
} else if (x - 3 >= 0 && matrix[y][x - 3] == null && b[0] == false && b[3] == false) {
//OESTE
cont++;
solver2(matrix, x, y, num, path, paths, cList);
} else if (y - 2 >= 0 && x + 2 < matrix.length && matrix[y - 2][x + 2] == null && b[4] == false) {
//NE
cont++;
solver2(matrix, x, y, num, path, paths, cList);
} else if (y + 2 < matrix.length && x + 2 < matrix.length && matrix[y + 2][x + 2] == null && b[5] == false) {
//SE
cont++;
solver2(matrix, x, y, num, path, paths, cList);
} else if (y + 2 < matrix.length && x - 2 >= 0 && matrix[y + 2][x - 2] == null && b[6] == false) {
//SO
cont++;
solver2(matrix, x, y, num, path, paths, cList);
} else if (y - 2 >= 0 && x - 2 >= 0 && matrix[y - 2][x - 2] == null && b[7] == false) {
//NO
cont++;
solver2(matrix, x, y, num, path, paths, cList);
}
}
if (cont == 0 && checkIfNumExists(num, matrix)) {
if (num != 1) {
num--;
path.pop();
cleanRecord(num + 1, matrix, cList);
cleanMatrixAbove(num, matrix, cList);
}
}
}
/**
* returns the coordenates of the num
*
* @param num
* @param matrix
* @return
*/
public static int[] getCoordenatePrevious(int num, Integer[][] matrix) {
for (int i = 0; i < matrix.length; i++) {
for (int j = 0; j < matrix.length; j++) {
if (matrix[i][j] != null && matrix[i][j] == num) {
int[] array = new int[2];
array[0] = j; //x
array[1] = i; //y
return array;
}
}
}
return null;
}
/**
* cleans the visited record of the num
*
* @param num
* @param matrix
* @param cList
*/
public static void cleanRecord(int num, Integer[][] matrix, CoordenateList cList) {
if (checkIfNumExists(num, matrix)) {
Coordenate c = cList.getCoordenateByKey(Integer.toString(getCoordenatePrevious(num, matrix)[1]) + "," + Integer.toString(getCoordenatePrevious(num, matrix)[0]));
c.cleanVisited();
}
}
/**
* sets null every number in the matrix that are bigger than num
*
* @param num
* @param matrix
* @param cList
*/
public static void cleanMatrixAbove(int num, Integer[][] matrix, CoordenateList cList) {
for (int i = 0; i < matrix.length; i++) {
for (int j = 0; j < matrix.length; j++) {
if (matrix[i][j] != null && matrix[i][j] > num) {
matrix[i][j] = null;
}
}
}
}
/**
* checks if the num exists in the matrix
*
* @param num
* @param matrix
* @return
*/
public static boolean checkIfNumExists(int num, Integer[][] matrix) {
for (int i = 0; i < matrix.length; i++) {
for (int j = 0; j < matrix.length; j++) {
if (matrix[i][j] != null && matrix[i][j] == num) {
return true;
}
}
}
return false;
}
再一次，我很抱歉这些巨大的代码，但我真的想尽可能多地提供信息。如有任何问题或疑问，请随时提出。
答案 0 :(得分：0)
如果在编译代码时遇到StackOverFlow错误，那么您可能会在编译器中发现错误。但是，在编译代码时，绝对不 收到StackOverFlow错误，当您 正在运行 代码时，您会收到错误
（递归是一个高级的计算机科学主题，但是如果你仍在努力学习编译程序和运行它时的概念，那么现在递归对你来说可能有点太高级了。只是一个想法。）
在你的solver2()函数中，你有一个可怕的嵌套if()语句，除了某些不太可能的情况外，它总会递归。
然后，你有另一个if()-else语句序列，除非所有测试条件都不成立，否则它们也会一直递归。
我认为没有人会花费所有时间来阅读并理解你所拥有的这种怪异，所以唯一可以建议的是在你的递归函数中添加更多条件，这将使它成为< em>更多可能会在某些时候避免递归，这样你的递归函数就不会永远地继续递归。 （也就是说，直到它耗尽堆栈。）