有一个二维数组long[50][50]，其中填充了从 0 到 100 的随机数。我需要找到从最大（或第一个最高）到最小的最长路径。您可以向上、向下、向左和向右移动。
我找到了如何找到单一方式：找到最大的最近数字（但不是更大，就是这样）并移动到那里。
public static int measure = 50;
public long[][] map = new long[measure][measure];
我的搬家方法：
private long moveUp(int x, int y) {
if (x >= measure || x == 0 || y == 0 || y >= measure) {
return -1;
}
return map[x - 1][y];
}
private long moveRight(int x, int y) {
if (x >= measure || x == 0 || y == 0 || y >= measure) {
return -1;
}
return map[x][y + 1];
}
private long moveDown(int x, int y) {
if (x >= measure || x == 0 || y == 0 || y >= measure) {
return -1;
}
return map[x + 1][y];
}
private long moveLeft(int x, int y) {
if (x >= measure || x == 0 || y == 0 || y >= measure) {
return -1;
}
return map[x][y - 1];
}
找到最近的最大：
private long rightWay(int x, int y) {
List<Long> pickList = new ArrayList<>();
long up = moveUp(x, y);
long right = moveRight(x, y);
long down = moveDown(x, y);
long left = moveLeft(x, y);
if (up != -1 && up < map[x][y]) {
pickList.add(moveUp(x, y));
}
if (right != -1 && right < map[x][y]) {
pickList.add(moveRight(x, y));
}
if (down != -1 && down < map[x][y]) {
pickList.add(moveDown(x, y));
}
if (left != -1 && left < map[x][y]) {
pickList.add(moveLeft(x, y));
}
if (pickList.size() == 0) {
return -1;
} else {
Collections.sort(pickList);
for (int i = 0; i < pickList.size(); i++) {
System.out.println("right way " + i + " -> " + pickList.get(i));
}
return pickList.get(pickList.size() - 1);
}
}
然后仅使用最近的最大值找到最长的方式：
private void findRoute(long[][] route, long current, int width, int height) {
System.out.println("width = " + width + " height = " + height);
long nextSpetHeight = rightWay(width, height);
System.out.println("max = " + nextSpetHeight);
if (nextSpetHeight == -1) {
return;
} else {
if (nextSpetHeight == moveUp(width, height)) {
findRoute(route, nextSpetHeight, width - 1, height);
way.add(nextSpetHeight);
}
if (nextSpetHeight == moveRight(width, height)) {
findRoute(route, nextSpetHeight, width, height + 1);
way.add(nextSpetHeight);
}
if (nextSpetHeight == moveDown(width, height)) {
findRoute(route, nextSpetHeight, width + 1, height);
way.add(nextSpetHeight);
}
if (nextSpetHeight == moveLeft(width, height)) {
findRoute(route, nextSpetHeight, width, height - 1);
way.add(nextSpetHeight);
}
}
}
的大小way将是此类路线的长度。但是现在我不知道如何从某个坐标中找到所有可能的路线以找到其中最长的路线。我的意思是我不知道回到“分叉”并继续另一条路线的最佳方式是什么。
我希望解释清楚。提前致谢。