c - 生成6个随机数时如何检查确保没有重复？

Question

我可以将随机数放入数组中，但我不知道如何检查以确保它们不重复。我打印出代码，但数组中没有数字(不打印任何内容)。

//puts random numbers into an array
i = 0, j = 0;
srand(time(NULL));
for (i = 0; i < arrSize; i++)
{
  randArr[i] = randNums(1,50);
}

i = 0;
for(i = 0; i < arrSize; i++)
{
  printf("%d ", randArr[i]);
}

printf("\n\n");

//checks to make sure there are no duplicates
i = 0, j = 0, k = 0, temp = 0;
for (i = 0; i < arrSize; i++)
{
  for (j = 1; j <= arrSize;)
  {
    if (randArr[j] == randArr[i])
    {
      for (k = j; k <= arrSize; k++)
      {
        temp = randNums(1,50);
        randArr[k + 1] = temp;
      }
      arrSize--;
    }
    else
      j++;
  }
}

//generates random numbers between the inputed max and min
int randNums(int min, int max)
{
  int result = 0, low = 0, high = 0;
  if (min < max)
  {
    low = min;
    high = max + 1;
  }
  else
  {
    low = max + 1;
    high = min;
  }
  result = (rand() % (high - low)) + low;
  return (result);
}

Answer 1

当心!对于这个问题有许多不同的解决方案，它们都有一个或另一个缺点。如果我要快速实现它，我会选择这样的东西(没有太多的 C 魔法):

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

#define SIZE (30)
#define RAND_MIN (1)
#define RAND_MAX (50)

static int randNums(int min, int max) {
  // ...
}

int main(void) {
  (void) srand(time(NULL));
  int arr[SIZE];
  int used = 0;
  while (used < SIZE) {
    int  num    = randNums(RAND_MIN, RAND_MAX);
    bool exists = false;
    for (int i = 0; i < used; ++i) {
      if (arr[i] == num)
        exists = true;
    }
    if (exists == false)
      arr[used++] = num;
  }
  for (int i = 0; i < SIZE; ++i)
    (void) printf("%d\n", arr[i]);
  return EXIT_SUCCESS;
}

希望对你有一点帮助:)