对于整数取绝对值是abs呀,怎么错了呢

题目

对于整数取绝对值是abs呀,怎么错了呢
提示错误:`abs' undeclared (first use this function)
#include
#include
int main()
{
freopen("data.in","r",stdin);
freopen("data.out","w",stdout);
int n,m;
while(scanf("%d%d",&m,&n)!=EOF)
{
long a[m][n];
int i,j;
int s=0,t=0;
long max;
for(i=0;i

答案

取绝对值是fabs（）函数!