建立目录树

dir1
dir1
dir1
file1
file2
dir2
file1
file2
dir3
file1
dir4
dir1
dir1
dir1
dir1
file1
file1
file2
file3
dir2
dir1
file1
dir2
file1
file2
file3
file4
dir3
file1
file2
file3
file1
file1
file2
file3

#include <io.h>
#include <stdio.h>
#include <assert.h>
// #include <direct.h> // vs 下使用

struct FileNode {
char name[255];
FileNode *pParent;
FileNode *pChild;
FileNode *pNextBrother;
};

void DestroyDirStruct(FileNode *node) {
if (node == nullptr) return;

DestroyDirStruct(node->pChild);
DestroyDirStruct(node->pNextBrother);
delete node;
}

int main() {
char *filename = "dir_struct";
FileNode * DirStruct = nullptr;
FileNode * pCurNode = nullptr;
char name[255];
int level;
int cur_level;

int old = _dup(0);
freopen(filename, "r", stdin);
while (gets(name) != nullptr) {
char *pch = name;
while (*pch == '\t') ++pch;
cur_level = pch-name;

FileNode *node = new FileNode;
memset(node, 0, sizeof(FileNode));
strcpy(node->name, pch);

if (cur_level == 0) {
DirStruct = node;
}
else {
if (cur_level - level == 1) {
pCurNode->pChild = node;
node->pParent = pCurNode;
}
else if (cur_level - level == 0) {
pCurNode->pNextBrother = node;
node->pParent = pCurNode->pParent;
}
else if (cur_level - level < 0) {
for (int i=level-cur_level; i>0; --i)
pCurNode = pCurNode->pParent;
pCurNode->pNextBrother = node;
node->pParent = pCurNode->pParent;
}
else {
assert(false);
}
}
pCurNode = node;
level = cur_level;
}
fclose(stdin);
_dup2(old, 0);

pCurNode = DirStruct;
while (pCurNode) {
if (strstr(pCurNode->name, "dir") != '\0') {
mkdir(pCurNode->name);
}
else if (strstr(pCurNode->name, "file") != '\0') {
fclose(fopen(pCurNode->name, "w"));
}

if  (pCurNode->pChild!=nullptr) {
chdir(pCurNode->name);
pCurNode = pCurNode->pChild;
}
else if (pCurNode->pNextBrother != nullptr) {
pCurNode = pCurNode->pNextBrother;
}
else {
chdir("..");
pCurNode = pCurNode->pParent->pNextBrother;
}
}

DestroyDirStruct(DirStruct);
}