带配额的文件系统 第21次CCF-CSP计算机软件能力认证

过了一半测试用例

1.检查孩子和后代配额用dfs递归就行
2.回退操作使用string承接结果如果为N 就pop_back child

#include<iostream>
#include<unordered_map>
#include<unordered_set>
#include<bits/stdc++.h>
using namespace std;struct node {int Class; // 0:目录文件 1:普通文件 2:代表根目录string name; // 文件名称int size; // 文件大小 目录文件为0int LD; // 目录配额int LR; // 后代配额vector<node*> child; // 孩子文件node() {}node(int c, string n, int size) : Class(c), name(n), size(size) { LD = 0; LR = 0; }
};vector<string> change(string s) {vector<string> res;if (s.size() == 1) return res; // 根目录情况size_t start = 1; // 跳过第一个'/'size_t end = s.find("/", start);while (end != string::npos) {res.push_back(s.substr(start, end - start));start = end + 1;end = s.find("/", start);}if (start < s.size()) {res.push_back(s.substr(start));}return res;
}struct node* root = new node(2, "root", 0);// 计算目录的直接孩子中普通文件的总大小
int calcChildSize(node* dir) {int total = 0;for (node* child : dir->child) {if (child->Class == 1) { // 普通文件total += child->size;}}return total;
}// 计算目录的所有后代中普通文件的总大小
int calcDescendantSize(node* dir) {int total = 0;for (node* child : dir->child) {if (child->Class == 1) { // 普通文件total += child->size;} else if (child->Class == 0) { // 目录文件total += calcDescendantSize(child);}}return total;
}// 检查配额是否满足
bool checkQuota(node* dir) {// 检查目录配额if (dir->LD > 0) {int childSize = calcChildSize(dir);if (childSize > dir->LD) return false;}// 检查后代配额if (dir->LR > 0) {int descendantSize = calcDescendantSize(dir);if (descendantSize > dir->LR) return false;}// 递归检查所有子目录for (node* child : dir->child) {if (child->Class == 0 && !checkQuota(child)) {return false;}}return true;
}// 检查从根到指定路径的所有目录的配额
bool checkQuotaOnPath(vector<string> file_path, int file_size, int depth, node* now) {if (depth == file_path.size()) {return checkQuota(root);}// 模拟添加文件后检查配额if (depth == file_path.size() - 1) {// 检查当前目录的目录配额if (now->LD > 0) {int childSize = calcChildSize(now) + file_size;// 检查是否有同名文件需要替换for (node* child : now->child) {if (child->name == file_path[depth] && child->Class == 1) {childSize -= child->size; // 减去原文件大小break;}}if (childSize > now->LD) return false;}// 检查所有祖先目录的后代配额return checkQuota(root);}// 继续向下查找for (node* child : now->child) {if (child->Class == 0 && child->name == file_path[depth]) {return checkQuotaOnPath(file_path, file_size, depth + 1, child);}}// 需要创建新目录的情况，继续检查return checkQuota(root);
}string dfs_add(vector<string> file_path, int file_size, int depth, node* now) {if (file_path.size() == 0) return "N";if (depth == file_path.size() - 1) {// 到达目标目录，检查是否存在同名文件for (node* child : now->child) {if (child->name == file_path[file_path.size() - 1]) {if (child->Class == 1) {// 替换普通文件child->size = file_size;return checkQuota(root) ? "Y" : "N";} else {// 同名目录存在，无法创建return "N";}}}// 创建新的普通文件node* temp = new node(1, file_path[file_path.size() - 1], file_size);now->child.push_back(temp);// 检查配额if (checkQuota(root)) {return "Y";} else {// 配额不满足，撤销操作now->child.pop_back();delete temp;return "N";}}// 查找下一级目录for (node* child : now->child) {if (child->Class == 0 && child->name == file_path[depth]) {return dfs_add(file_path, file_size, depth + 1, child);} else if (child->Class == 1 && child->name == file_path[depth]) {// 路径中有普通文件阻挡return "N";}}// 需要创建新目录node* temp = new node(0, file_path[depth], 0);now->child.push_back(temp);string result = dfs_add(file_path, file_size, depth + 1, temp);if (result == "N") {// 创建失败，撤销目录创建now->child.pop_back();delete temp;}return result;
}void deleteNode(node* n) {for (node* child : n->child) {deleteNode(child);}delete n;
}string dfs_del(vector<string> file_path, int depth, node* now) {if (file_path.size() == 0) return "Y";if (depth == file_path.size() - 1) {for (auto it = now->child.begin(); it != now->child.end(); ++it) {if ((*it)->name == file_path[file_path.size() - 1]) {deleteNode(*it);now->child.erase(it);return "Y";}}return "Y"; // 文件不存在也返回Y}// 查找下一级目录for (node* child : now->child) {if (child->name == file_path[depth]) {return dfs_del(file_path, depth + 1, child);}}return "Y"; // 路径不存在也返回Y
}node* findNode(vector<string> file_path, int depth, node* now) {if (depth == file_path.size()) {return now;}for (node* child : now->child) {if (child->name == file_path[depth]) {return findNode(file_path, depth + 1, child);}}return nullptr;
}string dfs_set(vector<string> file_path, int ld, int lr) {node* target = findNode(file_path, 0, root);if (target == nullptr || target->Class != 0) {return "N"; // 目录不存在或不是目录}// 保存原配额值int oldLD = target->LD;int oldLR = target->LR;// 设置新配额值target->LD = ld;target->LR = lr;// 检查配额是否满足if (checkQuota(root)) {return "Y";} else {// 恢复原配额值target->LD = oldLD;target->LR = oldLR;return "N";}
}int main() {int n;cin >> n;while (n--) {string opt;cin >> opt;if (opt == "C") {string file_path;int file_size;cin >> file_path >> file_size;cout << dfs_add(change(file_path), file_size, 0, root) << endl;}else if (opt == "R") {string file_path;cin >> file_path;cout << dfs_del(change(file_path), 0, root) << endl;}else {string file_path;int ld, lr;cin >> file_path >> ld >> lr;cout << dfs_set(change(file_path), ld, lr) << endl;}}return 0;
}