骰子游戏号码不是随机的

Question

Basically I am supposed to simulate a program that rolls three dice, add it up. Then I will have the user guess if the next roll is higher, lower, same or if they just want to quit. I am having two problems.

1. The numbers are not random, obviously this is a big mistake on my part but I can't seem to figure it out. I am thinking I do not need the second inclusion of 3 dice pairs? They don't help at all anyways.

2. Regardless, my program goes through all of the if/else if statements all at once. Obviously I do not want this to happen.

---

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

int main ()
{
    int diceOne, diceTwo, diceThree, diceSum=0, timesCorrect=0, choice; 
    int newDiceOne, newDiceTwo, newDiceThree, newDiceSum;

    srand( time(NULL) );

    diceOne      = rand() % 6 + 1;
    diceTwo      = rand() % 6 + 1;
    diceThree    = rand() % 6 + 1;
    newDiceOne   = rand() % 6 + 1;
    newDiceTwo   = rand() % 6 + 1;
    newDiceThree = rand() % 6 + 1;

    printf("The three dice rolls: %d, %d, %d", diceOne, diceTwo, diceThree);
    diceSum = diceOne + diceTwo + diceThree;
    printf("\nTotal sum of dice is %d\n", diceSum);

    do {
        printf("Guess higher(1), lower(2), same(3) or quit?(4)\n");
        printf(" You have been correct %d times\n", timesCorrect);
        scanf("%d", &choice);

        printf("The three dice rolls: %d, %d, %d", newDiceOne, newDiceTwo, newDiceThree);
        newDiceSum= newDiceOne + newDiceTwo + newDiceThree;
        printf("\nTotal sum of dice is %d\n", newDiceSum);

        if (choice == 1)
        {
            if (newDiceSum > diceSum);
                timesCorrect++;
            printf("You are correct!\n");
        }
        else if (newDiceSum < diceSum); 
        {
            printf("You are incorrect, sorry!\n");
        }

        if (choice == 2)
        {
            if (newDiceSum < diceSum);
                timesCorrect++;
            printf("You are correct!\n");
        }
        else if (newDiceSum > diceSum); 
        {
            printf("You are incorrect, sorry!\n");
        }

        if (choice == 3)
        {
            if (newDiceSum == diceSum);
                timesCorrect ++;
            printf("You are correct!\n");
        }
        else if (newDiceSum != diceSum); 
        {
            printf("You are incorrect, sorry!\n");
        }

        if (choice == 4)
        {
            printf("Thanks for playing!!!!!!\n");
            system("pause");

            return 0;
        }
    } while (choice!= 4 );
}

Answer 1

You have an extra semicolon after the else if conditionals, like here

else if (newDiceSum < diceSum); 
                /*            ^ this should not be here */

If you use a compiler with good diagnostic capabilities and enable warnings, it should warn you about that " typo ", if you want to leave the block empty use braces like

else if (newDiceSum < diceSum) {}

Also, you set the first dice with rand() and they are random values, but then you always use the same values in the loop.

Answer 2

The following code:

1. Handles error conditions

2. Eliminates unneeded variables

3. Cleanly compiles

4. Executes with out failing

---

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

int main ( void )
{
    int diceOne;
    int diceTwo;
    int diceThree;
    int diceSum=0;
    int timesCorrect=0;
    int choice;

    int newDiceSum;

    srand( time(NULL) );

    diceOne      = rand() % 6 + 1;
    diceTwo      = rand() % 6 + 1;
    diceThree    = rand() % 6 + 1;


    printf("The three dice rolls: %d, %d, %d", diceOne, diceTwo, diceThree);
    diceSum = diceOne + diceTwo + diceThree;
    printf("\nTotal sum of dice is %d\n", diceSum);

    do {
        printf("Guess higher(1), lower(2), same(3) or quit?(4)\n");
        printf(" You have been correct %d times\n", timesCorrect);
        if( 1 != scanf("%d", &choice) )
        { // then scanf failed
            perror( "scanf for choice failed" );
            exit( EXIT_FAILURE );
        }

        // implied else, scanf successful

        diceOne      = rand() % 6 + 1;
        diceTwo      = rand() % 6 + 1;
        diceThree    = rand() % 6 + 1;

        printf("The three dice rolls: %d, %d, %d", diceOne, diceTwo, diceThree);
        newDiceSum = diceOne + diceTwo + diceThree;
        printf("\nTotal sum of dice is %d\n", newDiceSum);

        switch( choice )
        {
        case 1:
            if (newDiceSum > diceSum)
            {
                timesCorrect++;
                printf("You are correct!\n");
            }
            else
            {
                printf("You are incorrect, sorry!\n");
            }
            break;

        case 2:
            if (newDiceSum < diceSum)
            {
                timesCorrect++;
                printf("You are correct!\n");
            }
            else
            {
                printf("You are incorrect, sorry!\n");
            }
            break;

        case 3:
            if (newDiceSum == diceSum)
            {
                timesCorrect ++;
                printf("You are correct!\n");
            }
            else
            {
                printf("You are incorrect, sorry!\n");
            }
            break;

        case 4:
            printf("Thanks for playing!!!!!!\n");
            system("pause");
            break;

        default:
            printf( " invalid choice, valid choices are 1...4\n");
            break;
        } // end switch
    } while (choice!= 4 );
    return(0);
} // end function: main