c - C 中通过函数实现随机数(初级程序员)

Question

我创建了一个简单的游戏，让用户猜测 1 到 10 之间的随机数。它运行良好，然后我将其调整为一个函数，该函数采用 2 个参数(一个高值和一个低值)来生成随机数数字。当函数应该返回随机数时，通过函数执行此操作始终返回作为参数输入的最大数字的值。这是我的代码:

#include "stdio.h"
#include "stdlib.h"
#include "time.h"

int main(void) {

  int storedNum, low, high, userGuess;

  printf("Welcome to my random numbers game! You will choose a lower number and a maximum number and me, the computer, will choose a random number between those two values for you to guess.\n\nFirst, choose the lowest value");
  scanf("%d", &low);
  printf("Now, choose the highest value");
  scanf("%d", &high);

  storedNum = randomNumbers(low, high);
  printf("We have guessed a number between %d and %d. Guess our number!: ", low, high);
  scanf("%d", &userGuess);

  while (userGuess != storedNum){
    if(userGuess < storedNum){
      printf("higher!: ");
      scanf("%d", &userGuess);
    }
    else{
      printf("Lower!: ");
      scanf("%d", &userGuess);
    }
  }

  printf("You are correct the number was %d!", storedNum);
  return 0;
}

int randomNumbers(int maxNum, int minNum){
  int number;
  srand(time(NULL));
  number = rand()%maxNum + minNum;
  return number;
}

只要我在主方法中生成随机数，代码就可以正常工作，但每当我通过函数使用它时，我总是得到相同的返回值。我认为问题在于函数内部的种子，但我不完全确定。即使这是问题所在，我也不确定如何解决这个问题并使我的代码正常工作。

基本上，我正在尝试编写一个可以在其他程序中重用的函数来生成 x 和 y 之间的随机数。

这里是一些示例输出:

Welcome to my random numbers game! You will choose a lower number and a maximum number and me, the computer, will choose a random number between those two values for you to guess.

First, choose the lowest value 1
Now, choose the highest value 10
We have guessed a number between 1 and 10. Guess our number!:  5
higher!:  8
higher!:  9
higher!:  10
You are correct the number was 10! 

无论我输入什么数字，它总是返回最大值(在本例中为 10)。预先感谢您提供的任何和所有帮助，我希望这篇文章能让您满意。

Answer 1

 rand()%maxNum + minNum;

rand ()将生成 0 之间的数字和RAND_MAX .

rand%maxNum将是一个数字<= min(rand(),maxNum-1)

所以你会得到的数字是 <=min(rand(),maxNum-1) + minNum这可能超过maxNum

• 要获得 MIN 和 MAX 之间的正确随机数，最好遵循此公式:

  (rand() % (MAX - MIN + 1)) + MIN;