函数名: labs
功 能: 取长整型绝对值
用 法: #include <math.h>
long labs(long n);
程序例:
#include <stdio.h>
#include <math.h>
int main(void)
{
long result;
long x = -12345678L;
result= labs(x);
printf("number: %ld abs value: %ld\n",
x, result);
return 0;
}