Implemented doubly linked list, fixed issued with singly linked list. Added some nicer visualization for both of them.

5 files changed, 130 insertions, 9 deletions

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..ec5930a
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,31 @@
+CC=egcc
+CFLAGS_TESTBIN=-O3 -Wfatal-errors -Wall -Werror -Wextra -g -Wpedantic -std=c99
+CFLAGS=-O3 -flto -march=native -DNDEBUG -fomit-frame-pointer -s -std=gnu99
+TARGET1=s_linkedlist
+TARGET2=d_linkedlist
+TESTTARGET1=s_linkedlist-t
+TESTTARGET2=d_linkedlist-t
+INSTALL_DIRECTORY=/usr/local/bin
+MAKEFLAGS += -s
+SRCSL=s_linkedlist.c
+SRCDL=d_linkedlist.c
+
+all: release
+clean:
+	rm -f $(TARGET1) $(TARGET2)
+	rm -f test/$(TESTTARGET1) test/$(TESTTARGET2)
+
+tests:
+	
+	$(CC) $(CFLAGS_TESTBIN) $(SRCSL) -o test/$(TESTTARGET1)
+	$(CC) $(CFLAGS_TESTBIN) $(SRCDL) -o test/$(TESTTARGET2)	
+	echo "$(TESTTARGET) is done."
+
+release:
+	
+	$(CC) $(CFLAGS) $(SRCSL) -o $(TARGET1)
+	$(CC) $(CFLAGS) $(SRCDL) -o $(TARGET2)
+	
+	
+
+	
diff --git a/d_linkedlist.c b/d_linkedlist.c
new file mode 100644
index 0000000..025bbb9
--- /dev/null
+++ b/d_linkedlist.c
@@ -0,0 +1,76 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+
+// Singly linked list demo
+
+struct waster {
+    int gg;
+    struct waster *prev;
+    struct waster *next;
+};
+
+struct waster *newnode () {
+
+    struct waster *new = malloc(sizeof(struct waster));
+    return new; 
+}
+
+struct waster *llist (uint64_t count) {
+    
+    struct waster *wr1 = malloc(sizeof(struct waster));
+    struct waster *head = wr1;
+    wr1->gg = 0; // Data for first node
+    wr1->prev = NULL; // There is no previous node
+    wr1->next = newnode(); // Make new node, next points to it
+    struct waster *prv = wr1; // Make prv point to current node
+    wr1 = wr1->next; // Make wr1 point to next node
+
+    
+    for (uint64_t i = 1 ; i < count ; i++) { // Actual loop starts
+        
+        wr1->gg = i; // Data for 2nd node
+	wr1->prev = prv; // make prev point to prv = wr1 = last node
+        if (i == count-1) {
+	    wr1->next = NULL;
+	} else {
+	    wr1->next = newnode(); // Make next node, next points to it
+        }
+	prv = wr1; // prv points to current node
+        wr1 = wr1->next; // Make wr1 point to the next node
+        
+    }
+
+    wr1 = NULL;
+    return head;
+}
+
+void freellist(struct waster *wr1) {
+    //printf("freelist \n");
+    struct waster *save;
+    while (wr1 != NULL) {
+        save = wr1;
+        wr1 = wr1->next;
+        free(save);
+    }
+}
+
+int main () {
+
+    struct waster *wr1 = llist(20);
+    struct waster *p;
+    for (p = wr1 ; p != NULL ; p = p->next) {
+        void *prev = (void*)p->prev;
+	void *next = (void*)p->next;
+	printf("\n------%p----------",(void *)p);
+	printf("\ndata: %d\nprev: %p\nnext: %p\n", p->gg, prev, next);
+	printf("-----------------------------\n");
+    }
+    
+    freellist(wr1);
+    return 0;
+}
diff --git a/linked b/linked
deleted file mode 100755
index cbbae44..0000000
--- a/linked
+++ /dev/null
diff --git a/linked.c b/s_linkedlist.c
index 8f47a41..761a262 100644
--- a/linked.c
+++ b/s_linkedlist.c
@@ -6,12 +6,14 @@
 #include <stdbool.h>
 #include <string.h>
 
+// Singly linked list demo
+
 struct waster {
     int gg;
     struct waster *next;
 };
 
-void *newnode () {
+struct waster *newnode () {
 
     struct waster *new = malloc(sizeof(struct waster));
     return new; 
@@ -24,12 +26,16 @@ struct waster *llist (uint64_t count) {
     for (uint64_t i = 0 ; i < count ; i++) {
 
         wr1->gg = i; 
-        wr1->next = newnode(); // Make new node and assign address of the new node to the current one
-        wr1 = wr1->next; // Make save point to the next node
+        if (i == count-1) {
+	    wr1->next = NULL;
+	} else {
+	    wr1->next = newnode(); // Make new node and assign address of the new node to the current one
+        }
+	wr1 = wr1->next; // Make save point to the next node
         
     }
 
-    wr1->next = NULL;
+    wr1 = NULL;
     return head;
 }
 
@@ -45,12 +51,14 @@ void freellist(struct waster *wr1) {
 
 int main () {
 
-    struct waster *wr1 = llist(10);
+    struct waster *wr1 = llist(20);
     struct waster *p;
-    for (p = wr1 ; p->next != NULL ; p = p->next) {
-        printf("%d\n", p->gg);
+    for (p = wr1 ; p != NULL ; p = p->next) {
+        printf("\n------%p----------", (void*)p);
+	printf("\ndata: %d\nnext: %p\n", p->gg, (void*)p->next);
+	printf("-----------------------------\n");
     }
-
+    printf("\nHEAD: %p\n", (void*)wr1);
     freellist(wr1);
     return 0;
-}
\ No newline at end of file
+}
diff --git a/test/Makefile b/test/Makefile
new file mode 100644
index 0000000..48a5814
--- /dev/null
+++ b/test/Makefile
@@ -0,0 +1,6 @@
+all: release
+clean:
+	cd .. && make clean
+
+release:
+	cd .. && make tests