File Word Counter - Problem

Write a program that counts the total number of words in a text file. Your solution must handle various error conditions gracefully:

File not found: Return -1 if the file doesn't exist
Permission errors: Return -2 if you don't have read permissions
Empty files: Return 0 for empty files
Valid files: Return the total word count

A word is defined as any sequence of non-whitespace characters separated by spaces, tabs, or newlines. For example, "Hello world!" contains 2 words.

Implementation Notes:

Use appropriate try-catch blocks for error handling
Consider different types of whitespace as word separators
Handle edge cases like files with only whitespace

Input & Output

Example 1 — Valid File with Content

$ Input: filename = "document.txt"

› Output: 5

💡 Note: File contains "Hello world from TutorialsPoint!" which has 5 words when split by whitespace

Example 2 — File Not Found

$ Input: filename = "missing.txt"

› Output: -1

💡 Note: File doesn't exist in the system, return -1 as specified

Example 3 — Empty File

$ Input: filename = "empty.txt"

› Output: 0

💡 Note: File exists but contains no content or only whitespace, return 0

Constraints

Filename length ≤ 255 characters
File size ≤ 10 MB for practical purposes
Handle UTF-8 encoded text files
Must handle all common file system errors

Visualization

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Asked in

M Microsoft 35 G Google 28 a Amazon 22 A Apple 18

The key insight is using proper try-catch blocks to handle all file operation errors gracefully. The optimal approach uses structured exception handling to distinguish between different error types (file not found, permission denied) while efficiently counting words character by character. Time: O(n), Space: O(1) where n is the file size.

Common Approaches

✓ Basic File Reading with Manual Error Checking

⏱️ Time: O(n) Space: O(n)

Attempt to read the file directly and handle errors through return codes or basic checks. This approach lacks structured error handling and may miss edge cases.

Structured Error Handling with Try-Catch

⏱️ Time: O(n) Space: O(1)

Implement comprehensive try-catch blocks to handle all error conditions gracefully. Use efficient file reading and word counting techniques with proper resource management.

Basic File Reading with Manual Error Checking — Algorithm Steps

Open file directly
Read content manually
Count words by splitting on whitespace
Handle errors reactively

Visualization

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Step-by-Step Walkthrough

Direct File Access

Try to open file without preparation

Read and Process

Read entire content and split on whitespace

Handle Errors

React to errors as they occur

Code -

solution.c — C

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

int solution(char* filename) {
    FILE* file = fopen(filename, "r");
    
    // Check if file can be opened
    if (file == NULL) {
        return -1;  // File not found or permission error
    }
    
    // Get file size
    fseek(file, 0, SEEK_END);
    long size = ftell(file);
    fseek(file, 0, SEEK_SET);
    
    // Handle empty file
    if (size == 0) {
        fclose(file);
        return 0;
    }
    
    // Read file content
    char* content = malloc(size + 1);
    fread(content, 1, size, file);
    content[size] = '\0';
    fclose(file);
    
    // Count words
    int wordCount = 0;
    int inWord = 0;
    
    for (int i = 0; i < size; i++) {
        if (isspace(content[i])) {
            inWord = 0;
        } else {
            if (!inWord) {
                wordCount++;
                inWord = 1;
            }
        }
    }
    
    free(content);
    return wordCount;
}

int main() {
    char filename[256];
    fgets(filename, sizeof(filename), stdin);
    filename[strcspn(filename, "\n")] = 0;  // Remove newline
    
    int result = solution(filename);
    printf("%d\n", result);
    
    return 0;
}

Time & Space Complexity

Time Complexity

⏱️

O(n)

Must read through entire file content once where n is file size

✓ Linear Growth

Space Complexity

O(n)

Stores entire file content in memory for processing

✓ Linear Space

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File Word Counter - Problem

Input & Output

Constraints

Visualization

Related Problems

Common Approaches

Basic File Reading with Manual Error Checking — Algorithm Steps

Visualization

Code -

Time & Space Complexity

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