Adding C to the tree traversal and verlet

chapters/computational_physics/verlet.md

@@ -432,3 +432,72 @@ xlabel('Time (s)'); ylabel('Height (m)');
 Submitted by P. Mekhail
 
 ![Verlet LabVIEW](verlet_labview.png)
+
+#### C
+
+```
+#include <stdio.h>
+
+// Simple function for velocity-verlet
+void verlet(double pos, double acc, double dt){
+
+    // Note that we are using a temp variable for the previous position
+    double prev_pos, temp_pos, time;
+    prev_pos = pos;
+    time = 0;
+
+    while (pos > 0){
+        time += dt;
+        temp_pos = pos;
+        pos = pos*2 - prev_pos + acc * dt * dt;
+        prev_pos = temp_pos;
+    }
+
+   printf("%f\n", time);
+
+}
+
+// Simple function for stormer-verlet
+void stormer_verlet(double pos, double acc, double dt){
+
+    double prev_pos, temp_pos, time, vel;
+    prev_pos = pos;
+    vel = 0;
+    time = 0;
+    while (pos > 0){
+        time += dt;
+        temp_pos = pos;
+        pos = pos*2 - prev_pos + acc * dt * dt;
+        prev_pos = temp_pos;
+
+        // The acceleration is constant, so the velocity is straightforward
+        vel += acc*dt;
+    }
+
+   printf("%f\n", time);
+
+}
+
+// Simple function for velocity-verlet
+void velocity_verlet(double pos, double acc, double dt){
+
+    double time, vel;
+    vel = 0;
+    time = 0;
+    while (pos > 0){
+        time += dt;
+        pos += vel*dt + 0.5*acc * dt * dt;
+        vel += acc*dt;
+    }
+
+   printf("%f\n", time);
+
+}
+
+int main(){
+    verlet(5.0, -10, 0.01);
+    stormer_verlet(5.0, -10, 0.01);
+    velocity_verlet(5.0, -10, 0.01);
+
+}
+```

chapters/fundamental_algorithms/tree_traversal.md

@@ -327,3 +327,164 @@ def main():
 
 main()
 ```
+
+### C
+
+```C
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct node{
+    struct node *children; // I chose a pointer to create a dynamic array
+    int children_num;
+    int ID;
+} node;
+
+// There is no stack or queue in c so I created my own
+typedef struct node_list{
+    node n;
+    struct node_list *last_list, *next_list;
+} node_list;
+
+typedef struct node_points{
+    node_list *start_point, *end_point;
+} node_points;
+
+void push(node_points *np, node *n){
+    // Adding node into a queue or a stack
+    node_list *temp = (node_list*)malloc(sizeof(node_list));
+    temp->n = *n;
+    temp->last_list = temp->next_list = NULL;
+
+    if(!np->end_point){
+	np->start_point = temp;
+    }else{
+	np->end_point->next_list = temp;
+	temp->last_list = np->end_point;
+    }
+    np->end_point = temp;
+}
+
+void stack_pop(node_points *np){
+    // Removing the last node_list of the stack
+    node_list *temp;
+    temp = np->end_point;
+    if(temp){
+	np->end_point = temp->last_list;
+	if(!np->end_point){
+	    np->start_point = NULL;
+	}
+	free(temp);
+    }
+}
+
+void queue_pop(node_points *np){
+    // Removing the first node_list of the queue
+    node_list *temp;
+    temp = np->start_point;
+    if(temp){
+	np->start_point = temp->next_list;
+	if(!np->start_point){
+	    np->end_point = NULL;
+	}
+	free(temp);
+    }
+}
+
+void create_tree(node *n, int num_row, int num_child) {
+    n->ID = num_row;
+    if(num_row == 0){
+	return;
+    }
+
+    // Creating children
+    // Using malloc to make an array of nodes with size num_child
+    n->children = (node *)malloc(num_child*sizeof(*n->children));
+    // When an array is made into a pointer you can't get it's size later
+    n->children_num = num_child;
+    for(int i = 0; i < num_child; ++i){
+        node child;
+        create_tree(&child, num_row - 1, num_child);
+        *(n->children + i) = child;
+    }
+}
+
+void DFS_recursive(node *n){
+    printf("%d\n", n->ID);
+
+    // Checking if the node's children exist
+    if(!n->children){
+        return;
+    }
+
+    for(int i = 0; i < n->children_num; ++i){
+        DFS_recursive((n->children + i));
+    }
+}
+
+void DFS_stack(node *n){
+    // Creating a stack and then setting its value to 0
+    node_points stack;
+    memset(&stack, 0, sizeof(node_points));
+    push(&stack, n);
+    node temp;
+
+    while(stack.start_point != NULL){
+	temp = stack.end_point->n;
+	printf("%d\n", temp.ID);
+	stack_pop(&stack);
+	for(int i=0; i < temp.children_num; ++i){
+	    // Checking if the node has any children
+	    if(!temp.children){
+		break;
+	    }
+	    push(&stack, temp.children + i);
+	}
+    }
+}
+
+void BFS_queue(node *n){
+    // Creating a queue and then setting its value to 0
+    node_points queue;
+    memset(&queue, 0, sizeof(node_points));
+    push(&queue, n);
+    node temp;
+
+    while(queue.start_point != NULL){
+	temp = queue.start_point->n;
+	printf("%d\n", temp.ID);
+	queue_pop(&queue);
+	for(int i = 0; i < temp.children_num; ++i){
+	    // Checking if the node has any children
+	    if(!temp.children){
+		break;
+	    }
+	    push(&queue, temp.children + i);
+	}
+    }
+}
+
+void destroy_tree(node *n){
+    // This function is for cleaning up all the nodes
+    if(n->ID == 0){
+	return;
+    }
+
+    for(int i = 0; i < n->children_num; ++i){
+	destroy_tree(n->children + i);
+    }
+    free(n->children);
+}
+
+int main() {
+    node root;
+    create_tree(&root, 3, 3);
+    //DFS_recursive(&root);
+    //DFS_stack(&root);
+    BFS_queue(&root);
+    destroy_tree(&root);
+
+    return 0;
+}
+```