/in/foo.cc: In function 'int main()':
/in/foo.cc:11:18: error: 'm' was not declared in this scope
       j = rand()%m+n     //n是起始值，n+m-1是终止值，m是随机数范围
                  ^
/in/foo.cc:11:20: error: 'n' was not declared in this scope
       j = rand()%m+n     //n是起始值，n+m-1是终止值，m是随机数范围
                    ^