c - 如何检测一个数字是否在C中的另外两个数字之间？

Question

如何检测用户输入的整数是否介于 2 个数字之间？

我试过这样做:

int x=3;
printf("Enter the size of the triangle: ");
scanf("%d", &size);
odd=size%2;

for(x=3;x<21;x++)
{
  if(x==size&&odd==1)
  {
     break;
  }
  else
  {
 printf("The size must be an odd number and be between\n3 and 21, inclusive, please try again\n\n");
     printf("Enter the size of the triangle: ");
     scanf("%d",&size);
     odd=size%2;
     x=3;
  } 
}  

但我唯一可以使用的输入是 3。

Answer 1

您已经在代码中获得了解决方案的所有部分:

if (size >= 3 && size <= 21) {
   // size is between 3 and 21 inclusive
} else {
   // size is less than 3 or more than 21
}

如果你也想保证是奇数，可以加上条件:

if ((size >= 3) && (size <= 21) && (size % 2 == 1)) {
   // size is between 3 and 21 inclusive, and odd
} else {
   // size is less than 3 or more than 21 or even
}