/in/foo.c: In function 'main':
/in/foo.c:5:9: warning: missing terminating " character
  printf("请输入2个数字：\n);
         ^
/in/foo.c:5:9: error: missing terminating " character
  printf("请输入2个数字：\n);
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~
/in/foo.c:6:24: error: expected ')' before ';' token
  scanf("%d %d",&x1,&x2);
                        ^
/in/foo.c:6:2: warning: passing argument 1 of 'printf' makes pointer from integer without a cast [-Wint-conversion]
  scanf("%d %d",&x1,&x2);
  ^~~~~
In file included from /in/foo.c:1:0:
/usr/include/stdio.h:364:12: note: expected 'const char * restrict' but argument is of type 'int'
 extern int printf (const char *__restrict __format, ...);
            ^~~~~~
/in/foo.c:22:6: error: expected ';' before '}' token
      }
      ^
/in/foo.c:4:16: warning: unused variable 't' [-Wunused-variable]
  int x1,x2,c,m,t;
                ^
/in/foo.c:4:14: warning: unused variable 'm' [-Wunused-variable]
  int x1,x2,c,m,t;
              ^
/in/foo.c:4:12: warning: unused variable 'c' [-Wunused-variable]
  int x1,x2,c,m,t;
            ^