问题描述
下面的函数打印所有子路径。是否可以仅显示完整路径,即 A->B->C(包括下面的必需输出)。
findpaths(List<Integer>[] adjacencyList,int u,List<String> path) throws IOException {
print(path+" "+path.size()+ "\n");
for (Integer v : adjacencyList[u]) {
path.add(mapIndexToCode.get(v));
findpaths(adjacencyList,v,path,writer);
path.remove(mapIndexToCode.get(v));
}
}
OUTPUT
A 1
A B 2
A B C 3
E 1
E F 2
required OUTPUT
A B C 3
E F 2
解决方法
您可以在打印前添加一个条件来检查您是否在路径的末尾:
findPaths(List<Integer>[] adjacencyList,int u,List<String> path) throws IOException {
if (adjacencyList[u].isEmpty()) {
print(path+" "+path.size()+ "\n");
}
else {
for (Integer v : adjacencyList[u]) {
path.add(mapIndexToCode.get(v));
findPaths(adjacencyList,v,path,writer);
path.remove(mapIndexToCode.get(v));
}
}
}