【cs 50】lab5 problemset5

（1）lab5 - inheritance

// Simulate genetic inheritance of blood type

#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

// Each person has two parents and two alleles
typedef struct person
{
    struct person *parents[2];
    char alleles[2];
}
person;

const int GENERATIONS = 3;
const int INDENT_LENGTH = 4;

person *create_family(int generations);
void print_family(person *p, int generation);
void free_family(person *p);
char random_allele();

int main(void)
{
    // Seed random number generator
    srand(time(0));

    // Create a new family with three generations
    person *p = create_family(GENERATIONS);

    // Print family tree of blood types
    print_family(p, 0);

    // Free memory
    free_family(p);
}

// Create a new individual with `generations`
person *create_family(int generations)
{
    // TODO: Allocate memory for new person
    person *new =  malloc(sizeof(person));
    //char mid = "0";
    int random = 0;
    // If there are still generations left to create
    if (generations > 1)
    {
        // Create two new parents for current person by recursively calling create_family
        person *parent0 = create_family(generations - 1);
        person *parent1 = create_family(generations - 1);

        // TODO: Set parent pointers for current person
        new->parents[0] = parent0;
        new->parents[1] = parent1;
        // TODO: Randomly assign current person's alleles based on the alleles of their parents
        //mid = alleles[1];
        random = rand()%2;
        new->alleles[0] = parent0->alleles[random];
        random = rand()%2;
        new->alleles[1] = parent1->alleles[random];
    }

    // If there are no generations left to create
    else
    {
        // TODO: Set parent pointers to NULL
        new->parents[0] = NULL;
        new->parents[1] = NULL;
        // TODO: Randomly assign alleles
        new->alleles[0] = random_allele();
        new->alleles[1] = random_allele();
    }

    // TODO: Return newly created person
    return new;
   // return NULL;
}

// Free `p` and all ancestors of `p`.
void free_family(person *p)
{
    // TODO: Handle base case
    if(p == NULL){
        return;
    }
    // TODO: Free parents recursively
    free_family(p->parents[0]);
    free_family(p->parents[1]);
    // TODO: Free child
    free(p);

}

// Print each family member and their alleles.
void print_family(person *p, int generation)
{
    // Handle base case
    if (p == NULL)
    {
        return;
    }

    // Print indentation
    for (int i = 0; i < generation * INDENT_LENGTH; i++)
    {
        printf(" ");
    }

    // Print person
    if (generation == 0)
    {
        printf("Child (Generation %i): blood type %c%c\n", generation, p->alleles[0], p->alleles[1]);
    }
    else if (generation == 1)
    {
        printf("Parent (Generation %i): blood type %c%c\n", generation, p->alleles[0], p->alleles[1]);
    }
    else
    {
        for (int i = 0; i < generation - 2; i++)
        {
            printf("Great-");
        }
        printf("Grandparent (Generation %i): blood type %c%c\n", generation, p->alleles[0], p->alleles[1]);
    }

    // Print parents of current generation
    print_family(p->parents[0], generation + 1);
    print_family(p->parents[1], generation + 1);
}

// Randomly chooses a blood type allele.
char random_allele()
{
    int r = rand() % 3;
    if (r == 0)
    {
        return 'A';
    }
    else if (r == 1)
    {
        return 'B';
    }
    else
    {
        return 'O';
    }
}

(2)problemset5 speller

// Implements a dictionary's functionality

#include <ctype.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include "dictionary.h"

// Represents a node in a hash table
typedef struct node
{
    char word[LENGTH + 1];
    struct node *next;
}
node;

// TODO: Choose number of buckets in hash table
const unsigned int N = 26;
unsigned int count = 0;

// Hash table
node *table[N];

// Returns true if word is in dictionary, else false
bool check(const char *word)
{
    // TODO
    char copy[strlen(word)+1];
    for(int i=0;i<strlen(word);i++){
        copy[i] = tolower(word[i]);
    }
    int n = hash(copy);
    node *tmp = table[n];
    /*for(node *tmp = table[n];tmp!=NULL;tmp = tmp->next){
        if(strcasecmp(tmp->word,word)==0){
            return true;
        }
        else{
            continue;
        }
    }*/
    while(tmp!=NULL){
        if(strcasecmp(word,tmp->word)==0){
            return true;
        }
        tmp = tmp->next;
    }
    return false;
}

// Hashes word to a number
unsigned int hash(const char *word)
{
    // TODO: Improve this hash function
   return toupper(word[0]-'A');
}

// Loads dictionary into memory, returning true if successful, else false
bool load(const char *dictionary)
{
    // TODO
    FILE *dic = fopen(dictionary,"r");
    if(dic == NULL){
        return false;
    }
    char c;
    int index = 0;
    int n = 0;
    char dic_word[LENGTH+1];

    while (fscanf(dic,"%s",dic_word)!=EOF){
        node* h = malloc(sizeof(node));
        if(h==NULL){
            return false;
        }
        strcpy(h->word,dic_word);
        h->next = NULL;
        n = hash(dic_word);
        table[n] = h;
        //free(h);
        count++;
    }
    fclose(dic);
    //free(h);
    return true;
}

// Returns number of words in dictionary if loaded, else 0 if not yet loaded
unsigned int size(void)
{
    // TODO

    return count;
}

// Unloads dictionary from memory, returning true if successful, else false
bool unload(void)
{
    // TODO

    for(int i=0;i<N;i++){
        while(table[i]!=NULL){
            node *temp = table[i]->next;
            free(table[i]);
            table[i] = temp;
        }
    }
    return true;
}

提示：