quiz1 Cheat Sheet by failboatz

Declaring a struct:
    typedef struct {
        int x;
        int y;
    } point;

Declaring a variable and accessing members:
    point first;
    first.x = 1;
    first.y = 4;
    printf("(%d, %d) \n", first.x, first.y);

Hashtable:
    typedef struct _node 
    {
        char word[50]; // 50-char word
        struct _node *next;
    } 
    node;
Tree:
    typedef struct _tree3 {
        bool valid; // exists or not
        struct _tree3 *child1;
        struct _tree3 *child2;
        struct _tree3 *child3; 
    } 
    tree3;
Trie:
    typedef struct _btrie { 
        bool valid;
        struct _btrie *children[2]; 
    } 
    btrie;

Pop:
int pop(void)
{
    if (stack.size == 0)
        return -1;
    return stack.numbers[--stack.size];
}
Push:
bool push(int n)
{
    if (stack.size == CAPACITY || n < 0)
        return false;
    stack.numbers[stack.size++] = n;
    return true;
}

Declaration and initialization:
    int a = 14;
    int b = 15;
    int * iPtr;
    iPtr = &a;
    int * anotherPtr = &b;

Accessing pointers and values:
// assign an address to another pointer
    anotherPtr = iPtr;
// change the value stored in the memory
// location being pointed to
    *iPtr = 3;
// print the address held be a pointer
    printf("%x \n", iPtr);
// print the value being pointed to
    printf("%d \n", *iPtr);

Declaring a FILE pointer:
    FILE * inputFile;
    FILE * outputFile;
Opening a file:
    inputFile = fopen("file1.txt", "r");
    outputFile = fopen("file2.txt", "w");
Input / Output:
    fscanf(inputFile, "%d", &x);
    fprintf(outputFile, "%f \n", 3.14);
Closing a file:
    fclose(inputFile);
    fclose(outputFile);