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#include <iostream> #include <vector> #include <iomanip> class FileSystem { public: FileSystem(int totalBlocks) : blocks(totalBlocks, false) {} // Contiguous Allocation bool allocateContiguous(int fileSize, int& startBlock) { for (int i = 0; i <= blocks.size() - fileSize; ++i) { bool canAllocate = true; for (int j = i; j < i + fileSize; ++j) { if (blocks[j]) { canAllocate = false; break; } } if (canAllocate) { startBlock = i; for (int j = i; j < i + fileSize; ++j) { blocks[j] = true; } return true; } } return false; } // Linked Allocation bool allocateLinked(const std::vector<int>& fileBlocks, std::vector<int>& fileTable) { fileTable.clear(); for (int block : fileBlocks) { if (block >= blocks.size() || blocks[block]) { return false; } blocks[block] = true; fileTable.push_back(block); } return true; } // Indexed Allocation bool allocateIndexed(const std::vector<int>& fileBlocks, std::vector<int>& indexTable) { indexTable.clear(); for (int block : fileBlocks) { if (block >= blocks.size() || blocks[block]) { return false; } blocks[block] = true; indexTable.push_back(block); } return true; } void printBlocks() const { std::cout << "Block Status:\n"; for (int i = 0; i < blocks.size(); ++i) { std::cout << "Block " << i << ": " << (blocks[i] ? "Allocated" : "Free") << "\n"; } } private: std::vector<bool> blocks; }; int main() { int totalBlocks; std::cout << "Enter total number of blocks in the file system: "; std::cin >> totalBlocks; FileSystem fs(totalBlocks); int choice; std::cout << "Select allocation method:\n"; std::cout << "1. Contiguous Allocation\n"; std::cout << "2. Linked Allocation\n"; std::cout << "3. Indexed Allocation\n"; std::cout << "Enter choice (1-3): "; std::cin >> choice; if (choice == 1) { int fileSize, startBlock; std::cout << "Enter file size for contiguous allocation: "; std::cin >> fileSize; if (fs.allocateContiguous(fileSize, startBlock)) { std::cout << "File allocated starting at block " << startBlock << "\n"; } else { std::cout << "Allocation failed. Not enough contiguous space.\n"; } } else if (choice == 2) { int numBlocks; std::cout << "Enter number of blocks for linked allocation: "; std::cin >> numBlocks; std::vector<int> fileBlocks(numBlocks); std::cout << "Enter blocks for linked allocation: "; for (int& block : fileBlocks) { std::cin >> block; } std::vector<int> fileTable; if (fs.allocateLinked(fileBlocks, fileTable)) { std::cout << "File allocated with linked allocation.\n"; std::cout << "File Table: "; for (int block : fileTable) { std::cout << block << " "; } std::cout << "\n"; } else { std::cout << "Allocation failed. Invalid blocks or already allocated.\n"; } } else if (choice == 3) { int numBlocks; std::cout << "Enter number of blocks for indexed allocation: "; std::cin >> numBlocks; std::vector<int> fileBlocks(numBlocks); std::cout << "Enter blocks for indexed allocation: "; for (int& block : fileBlocks) { std::cin >> block; } std::vector<int> indexTable; if (fs.allocateIndexed(fileBlocks, indexTable)) { std::cout << "File allocated with indexed allocation.\n"; std::cout << "Index Table: "; for (int block : indexTable) { std::cout << block << " "; } std::cout << "\n"; } else { std::cout << "Allocation failed. Invalid blocks or already allocated.\n"; } } else { std::cout << "Invalid choice.\n"; } fs.printBlocks(); return 0; } |
Explanation
- Class
FileSystem:- Purpose: Simulates a file system with different file allocation methods.
- Attributes:
blocks: Vector indicating the status of each block (allocated or free).
- Methods:
allocateContiguous(int fileSize, int& startBlock): Allocates contiguous blocks for a file, if possible, and sets the start block.allocateLinked(const std::vector<int>& fileBlocks, std::vector<int>& fileTable): Allocates blocks for a file using linked allocation, maintaining a file table.allocateIndexed(const std::vector<int>& fileBlocks, std::vector<int>& indexTable): Allocates blocks for a file using indexed allocation, maintaining an index table.printBlocks(): Prints the status of all blocks in the file system.
- Main Function:
- Setup: Prompts the user for the total number of blocks in the file system.
- User Interaction: Allows the user to select an allocation method and input file blocks or size.
- Allocation: Executes the selected allocation method and prints the result.
- Block Status: Displays the final status of all blocks in the file system.
Usage
- File Allocation Simulation: Demonstrates three basic file allocation methods: contiguous, linked, and indexed.
- User Interaction: Provides options for different allocation methods and displays the outcome of the allocation process.