两个掷骰子模拟器

Question

#pragma warning(disable:4996)
// INCLUDES
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

// DEFINES
#define LOWER_DIE 1 // LOWER_DIE must be at least 1
#define UPPER_DIE 10
#define TRIALS 10000

// PROTOTYPES
int genRand(int, int);
int getTwoDieSum(int, int);
// MAIN
int main( int total) {
     int numberArray[2 * UPPER_DIE + 1] = { '0', '0', '0', '0', '0', '0', '0','0','0','0','0', '0', '0' };// holds frequency of rolls

     int roll = total;
     int i = 0;

     srand((unsigned int)time(NULL));
     for (i = 0; i < TRIALS; i++) {
          getTwoDieSum( LOWER_DIE, UPPER_DIE);
          numberArray[roll] == numberArray[roll] + 1;
     }

     printf("ROLL VALUE : FREQUENCY\n");
     printf("2\t: %d\n", numberArray[2]);
     printf("3\t: %d\n", numberArray[3]);
     printf("4\t: %d\n", numberArray[4]); 
     printf("5\t: %d\n", numberArray[5]);
     printf("6\t: %d\n", numberArray[6]);
     printf("7\t: %d\n", numberArray[7]);
     printf("8\t: %d\n", numberArray[8]);
     printf("9\t: %d\n", numberArray[9]);
     printf("10\t: %d\n", numberArray[10]);
     printf("11\t: %d\n", numberArray[11]);
     printf("12\t: %d\n", numberArray[12]);

     return 0;
}

// FUNCTION IMPLEMENTATIONS
int genRand(int lower, int upper) {
     int range = (upper - lower) + 1;
     return rand() % range + lower;

}

int getTwoDieSum( int lower, int upper) {
     int rollOne = 0;
     int rollTwo = 0;
     int total = 0;
     rollOne = genRand(lower, upper);
     rollTwo = genRand(lower, upper);
     total = rollOne + rollTwo;
     return total;
}

到目前为止，它应该是生成随机数，然后填充数组的正确元素。继续为所有 printf() 语句输出 48。有什么想法我搞砸了吗？我认为它在 genRand() 区域或 getTwoDieSum() 中。我需要使用以下外壳，我不确定一切都应该做什么，这就是我搞砸的原因。我也不确定 int lower 和 int upper 的来源：

int genRand(int lower, int upper) {
     int range = (upper - lower) + 1;
     return rand() % range + lower;
    }

我的问题更多是我在哪里搞砸了，int lower 和 int upper 来自哪里，我是否正确使用了随机种子生成器？

需要使用的外壳：

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

// DEFINES
#define LOWER_DIE 1 // LOWER_DIE must be at least 1
#define UPPER_DIE 10
#define TRIALS 10000

// PROTOTYPES
int genRand(int, int);
int getTwoDieSum();

// MAIN
int main() {
 int numberArray[2 * UPPER_DIE + 1]; // holds frequency of rolls

 // initialize numberArray

 // seed the random number generator

 // roll the dice and keep track of what was rolled in the array

 // display results

 return 0;
}

// FUNCTION IMPLEMENTATIONS
int genRand(int lower, int upper) {
 int range = (upper - lower) + 1;
 return rand() % range + lower;
}

int getTwoDieSum() {
 // YOUR IMPLEMENTATION GOES HERE 

Answer 1

您可以进一步改进您的代码。例如，计算两次滚动之和的函数可以简化为：

int getTwoDieSum( int lower, int upper ) {
    return genRand(lower, upper) + genRand(lower, upper);   
}

现在，getTwoDieSum 返回一个值，就像genRand 一样，您最好使用它。您的 main 函数可能如下所示：

// MAIN
int main() {

    // holds frequency of rolls
    int numberArray[2 * UPPER_DIE + 1] = {0};
    // The size of the array of frequency is set to 21, so that numberArray[20]
    // represents the frequency of roll 10+10.
    // The first two elements (numberArray[0] and numberArray[1]) are unused

    int size = sizeof(numberArray) / sizeof(int);
    int i;
    // If an array is partially initialized, elements that are not initialized
    // receive the value 0 of the appropriate type. Alternatively you can use:
    //
    // for ( i = 0; i < size; ++i ) {
    //     numberArray[i] = 0;
    // }
    // 
    // or simply
    // 
    // memset(numberArray,0,size);

    // seed the random number generator
    srand(time(NULL));

    // roll the dice and keep track of what was rolled in the array
    int roll;
    for (i = 0; i < TRIALS; i++) {
        roll = getTwoDieSum( LOWER_DIE, UPPER_DIE);
        ++numberArray[roll];
    }

    // display results
    printf("ROLL VALUE : FREQUENCY\n");
    for (i = 2; i < size; i++) {
        // numberArray[2] represent the frequency of roll 1+1,
        // while numberArray[20] is the frequency of roll 10+10
        printf("%d\t: %d\n", i, numberArray[i]);
        // add  ^^ the roll value
    }

    return 0;
}

一个典型的运行给出这个输出：

ROLL VALUE : FREQUENCY
2   : 99
3   : 179
4   : 273
5   : 390
6   : 513
7   : 587
8   : 678
9   : 777
10  : 902
11  : 1039
12  : 913
13  : 822
14  : 672
15  : 614
16  : 514
17  : 433
18  : 298
19  : 195
20  : 102

Answer 2

通过使用：

int main(void) {
     int numberArray[2 * UPPER_DIE + 1] = { '0', '0', '0', '0', '0', '0', '0','0','0','0','0', '0', '0' };// holds frequency of rolls


 int roll = 0;
 int i = 0;

 srand((unsigned int)time(NULL));
 for (i = 0; i < TRIALS; i++) {
      getTwoDieSum( LOWER_DIE, UPPER_DIE); 
      int main_total = getTwoDieSum( LOWER_DIE, UPPER_DIE);
      roll = main_total;
      numberArray[roll] = numberArray[roll] + 1;
 }

我能够让它正常工作。