猜數游戲2.0

程式產生一個1-100的隨機數，用戶嘗試儘可能少的次數猜出這個數。

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

#define MAX_NUMBER 100

//external variable
int secret_number;

//prototypes
void initialize_number_generator(void);
int new_secret_number(void);
void read_guesses(void);

int main(void)
{
    char command;
    int secret_number;

    printf("Guess the secret number between 1 and %d.\n\n", MAX_NUMBER);
    initialize_number_generator();
    do {
        secret_number = new_secret_number();
        printf("Anew number has been chosen.\n");
        read_guesses(secret_number);
        printf("Play again? (Y/S) ");
        scanf(" %c", &command);
        printf("\n");
    } while (command == 'y' || command == 'Y');

    return 0;
}

//initialize_number_generator:Initialize the random number generator using the time of day.

void initialize_number_generator(void)
{
    srand((unsigned)time(NULL));
}

//Returns a randomly chosen number between 1 and MAX_NUMBER.

int new_secret_number(void)
{
    return rand() % MAX_NUMBER + 1;
}

//read_guesses:Repeatedly reads user guesses and tells the user whether each guess is too low, too high, or correct. When the guess is correct, prints the total number of guesses and returns.

void read_guesses(int secret_number)
{
    int guess, num_guesses = 0;

    for (;;) {
        num_guesses++;
        printf("Enter guess: ");
        scanf("%d", &guess);
        if (guess == secret_number) {
            printf("You won in %d guesses!\n\n", num_guesses);
            return;
        }
        else if (guess < secret_number)
            printf("Too low, try again.\n");
        else
            printf("Too high, try again.\n");
    }
}