for chris

ll.c

#include <stdio.h>

// To execute C, please define "int main()"

typedef struct node{
  unsigned long val;
  struct node *next;
}node_t;

node_t* prepend(node_t *head, node_t *n) {
  if (n) {
    n->next = head;
    return n;
  } else {
    return head;
  }
}

node_t* insert(node_t *head, node_t *n) {
  node_t *orig = head;
  if (!head) {
    return n;
  } else if (n && n->val < head->val){
    //prepend case
    return prepend(head, n);
  }
  //insert case
  while(head && head->next) {
    if(n->val >= head->val && n->val < head->next->val) {
      n->next = head->next;
      head->next = n;
      return head;
    }
    head = head->next;
  }
  //append case
  head->next = n;
  return orig;
}

void print_node(node_t *head) {
  while(head){
    printf("node val is %lu\n", head->val);
    head = head->next;
  }
}


#define NUM_NODES 20

unsigned long test_cases[] = {
  0,
  99999,
  801,
  801,
  500,
  0,
  0,
  99999,
};
#define NUM_TEST_CASES (sizeof(test_cases)/sizeof(unsigned long))


int main() {
  static node_t nbuf[NUM_NODES];
  node_t *head = NULL;
  printf("\nsetting up\n");
  for (int i = NUM_NODES-1; i >= 0; i--) {
    node_t *n = &nbuf[i];
    n->val = 100 + i * 100;
    head = prepend(head, n);
  }
  print_node(head);
  
  printf("\ngenerating tests\n");
  static node_t tests[NUM_TEST_CASES];
  for(int i = 0; i < NUM_TEST_CASES; i++) {
    tests[i].val = test_cases[i];
    print_node(&tests[i]);
  }
  printf("\ninserted nodes\n");
  for(int i = 0; i < NUM_TEST_CASES; i++) {
    head = insert(head, &tests[i]);
  }
  print_node(head);
  
  return 0;
}