增加判断避免调用fread()缓冲区溢出

sms.c

@@ -173,7 +173,10 @@ void Load() //
 	fp1 = fopen("sql.txt", "rb");
 	fp2 = fopen("num.txt", "rb");
 	fread(&class_num, sizeof(int), 1, fp2);		   //读入信息
+	if (sizeof(CLASS) > sizeof(class_num))
+	{
 		fread(records, sizeof(CLASS), class_num, fp1); //读入信息
+	}
 	fclose(fp1);
 	fclose(fp2);
 }
@@ -268,6 +271,7 @@ void Buy()
 		system("pause");
 		Query();
 		printf("请输入要订票的班次(若无请输入0):\n");
+		num[0] = '\0';
 		scanf("%s", num);
 		for (i = 0; i < class_num; i++)
 			if (strcmp(num, records[i].number) == 0)