added weekly exercises of isp-ws25

c/isp-ws25/weeklies/week09/w09ex01.c

@@ -0,0 +1,104 @@
+/*
+In this task, you should get familiar with file I/O operations in C
+by writing a program that reads the text file sentences.txt and counts
+both the number of words and the number of characters (excluding line breaks).
+
+Tasks:
+- Open "sentences.txt" using fopen.
+  - if open fails (i.e., fopen returns NULL):
+    - Print the error message "Could not open file\n"
+    - return 1
+- User Input: line number that should be analyzed
+  - Line numbers are 1-based (if user enters "1", analyze first line)
+  - Read file (e.g., using fgetc)
+  - analyze correct line
+  - Count words separated by whitespace.
+  - Count characters (excluding line break).
+  - Close file properly after processing.
+  - Print word count and character count according to example output below.
+  - If entered line number is not in range line numbers of file:
+    - print "Could not analyze line\n".
+
+Examples:
+
+Line number to analyze: 5
+Word Count: 4
+Character Count: 22
+
+Line number to analyze: 1
+Word Count: 12
+Character Count: 80
+
+Line number to analyze: 22
+Word Count: 14
+Character Count: 76
+*/
+
+#include <ctype.h>
+#include <stdio.h>
+#include <string.h>
+
+int main(void)
+{
+  printf("Line number to analyze: ");
+  int line_number;
+  scanf("%d", &line_number);
+  if (line_number < 1)
+  {
+    printf("Could not analyze line\n");
+    return 0;
+  }
+
+  FILE *file = fopen("sentences.txt", "r");
+  if (file == NULL)
+  {
+    printf("Could not open file\n");
+    return 1;
+  }
+
+  int current_line = 1;
+  int word_count = 0;
+  int char_count = 0;
+  int character = 0;
+
+  int saw_char = 0;
+
+  while ((character = fgetc(file)) != EOF)
+  {
+    if(current_line != line_number && character != '\n') continue;
+    if (character == '\n')
+    {
+      if (current_line == line_number) break;
+      current_line++;
+      continue;
+    }    
+    if (current_line == line_number)
+    {
+      if (character != '\n') char_count++;
+      //It is rare to meet a Lannister who shares my enthusiasm for dead Lannisters.
+      if (isspace(character))
+      {
+        saw_char = 0;
+      }
+      else if (isgraph(character) && !saw_char)
+      {
+        word_count++;
+        saw_char = 1;
+        continue;
+      }
+    }
+  }
+
+  if (current_line < line_number)
+  {
+    printf("Could not analyze line\n");
+  }
+  else
+  {
+    printf("Word Count: %d\n", word_count);
+    printf("Character Count: %d\n", char_count);
+  }
+
+  fclose(file); 
+  return 0;
+}