online compiler and debugger for c/c++

#include <stdio.h> #include <stdlib.h> #include <pthread.h> #include <time.h> #include <limits.h> #include <string.h> int replacements = 0; void pageReplacementInitialization(int arr[], int **pages, int pageFault[], int size, int num_pages) { // Initialize pages for the first num_pages elements of arr for (int i = 0; i < num_pages && i < size; i++) { // Initialize pages for (int j = i; j < size; j++) { pages[i][j] = arr[i]; } pageFault[i] = 1; } } void pageReplacementAlgorithm(int arr[], int **pages, int pageFault[], int size, int num_pages) { int *distances = (int *)calloc(num_pages, sizeof(int)); // Array to store distances for each page for (int i = num_pages; i < size; i++) { // Check if current value exists in any page int fault = 1; // Assume page fault until proven otherwise for (int p = 0; p < num_pages; p++) { if (arr[i] == pages[p][i]) { fault = 0; break; } } if (fault) { pageFault[i] = 1; // Reset all distances for (int p = 0; p < num_pages; p++) { distances[p] = 0; } // Calculate distances for each page for (int j = i-1; j >= 0; j--) { for (int p = 0; p < num_pages; p++) { if (arr[j] == pages[p][j] && distances[p] == 0) { distances[p] = i-j; // Distance from current to previous } } } // Find page with maximum distance int max_distance = -1; int page_to_replace = 0; for (int p = 0; p < num_pages; p++) { if (distances[p] >= max_distance) { max_distance = distances[p]; page_to_replace = p; } } // Replace the page with maximum distance replacements++; // Update the chosen page with new value for (int k = i; k < size; k++) { pages[page_to_replace][k] = arr[i]; } // Keep other pages' values the same for (int p = 0; p < num_pages; p++) { if (p != page_to_replace) { pages[p][i] = pages[p][i-1]; } } } else { // No page fault, keep all current values for (int p = 0; p < num_pages; p++) { pages[p][i] = pages[p][i-1]; } } } free(distances); } void printArray(int arr[], int size) { for (int i = 0; i < size; i++) { printf("%d|", arr[i]); } printf("\n"); } void print2dArray(int *arr, int size) { for (int i = 0; i < size; i++) { printf("%d|", arr[i]); } printf("\n"); } void placeHolder(char *c, int size) { for (int i = 0; i < size; i++) { printf(" %s", c); } } int countPageFaults(int pageFault[], int size) { // loop through pagefault array to count number of pagefaults // 0 means no pagefault // 1 means pagefault int sum = 0; for (int i = 0; i < size; i++) { if (pageFault[i] == 1) { sum += 1; } } return sum; } int main() { int *arr, *pageFault; int **pages; // Array of pointers to hold multiple pages int size, num_pages; char input[1000]; // Get size from user // printf("Enter size: "); // scanf("%d", &size); // Get reference string printf("Enter reference string(separated by spaces): "); fgets(input, sizeof(input), stdin); // Use strtok to parse the string char *token = strtok(input, " \n"); int i = 0; // Get number of pages from user printf("Enter number of pages: "); scanf("%d", &num_pages); getchar(); // consume the newline //Avoid segmentation fault while(num_pages<=0) { printf("Number of pages must be 1 or larger \n"); printf("Enter number of pages: "); scanf("%d", &num_pages); getchar(); // consume the newline } // Dynamic allocation for reference string array arr = (int *)calloc(size, sizeof(int)); pageFault = (int *)calloc(size, sizeof(int)); // Allocate array of pointers for pages pages = (int **)malloc(num_pages * sizeof(int*)); // Allocate memory for each page for(int i = 0; i < num_pages; i++) { pages[i] = (int *)malloc(size * sizeof(int)); if (pages[i] == NULL) { printf("Memory allocation failed for page %d\n", i); return EXIT_FAILURE; } } while (token != NULL && i < size) { arr[i] = atoi(token); i++; token = strtok(NULL, " \n"); } size = i; // Check if allocation was successful and print array if (arr == NULL) { return EXIT_FAILURE; } else { pageReplacementInitialization(arr, pages, pageFault, size, num_pages); pageReplacementAlgorithm(arr, pages, pageFault, size, num_pages); // print arrays printf("\n\t Reference String:\t"); printArray(arr, size); printf("\t\t\t\t"); placeHolder("|", size); printf("\n\t LRU Output"); printf("\t\t"); placeHolder("|", size); printf("\n"); for(int i = 1; i < num_pages+1; i++) { printf("\t Page %d: \t", i); print2dArray(pages[i-1], size); } printf("\n"); printf("\t Page faults: \t"); printArray(pageFault, size); printf("\n\t\t\t The number of page faults = %d\n", countPageFaults(pageFault, size)); printf("\t\t\t The number of replacements = %d\n\n", replacements); } // Free all allocated memory free(arr); // Free each page for(int i = 0; i < num_pages; i++) { free(pages[i]); } // Free the array of pointers free(pages); return 0; }