#include <stdio.h>
#include<stdlib.h>
#include<time.h>
#define NUMBER 10
#define FILEPATH "./abc.txt"
char abb[4]={
'+','-','*','/'};
//打开文件函数
FILE *open_file(const char *str){
FILE *fp = fopen(FILEPATH,str);
if(fp==NULL){
perror("");
return NULL;