我如何使用C来验证两个数字之间的差不超过X

Question

我在下面粘贴了一些代码，简要介绍了我正在写的内容。我基本上需要说的是，如果当前MeterReading和当前MeterRead之间的差异>1000…给我一个错误。

例如。

printf("Usage is high at over 1000"); 

if (presentMeterReading < 0 || presentMeterReading > 9999)
printf("That's out of range. Meter readings should be between 0 - 9999 n");
if (previousMeterReading < presentMeterReading || presentMeterReading > previousMeterReading)
printf("Present readings should not be more than previous readings.");
if (dayReadingTaken > 12 || dayReadingTaken < 1)
printf("That's not a valid month.");

Answer 1

数学。

#include <math.h>

if (abs(presentMeterReading - currentMeterReading) > 1000) {
/* too much difference */
}