foo.c: In function 'main':
foo.c:6:17: warning: unknown conversion type character 'y' in format [-Wformat=]
    6 |         scanf("%y1,%y2",&y3);
      |                 ^
foo.c:6:21: warning: unknown conversion type character 'y' in format [-Wformat=]
    6 |         scanf("%y1,%y2",&y3);
      |                     ^
foo.c:6:15: warning: too many arguments for format [-Wformat-extra-args]
    6 |         scanf("%y1,%y2",&y3);
      |               ^~~~~~~~~
foo.c:8:17: error: 'temp' undeclared (first use in this function)
    8 |                 temp=x1;
      |                 ^~~~
foo.c:8:17: note: each undeclared identifier is reported only once for each function it appears in
foo.c:15:24: warning: unknown conversion type character 'y' in format [-Wformat=]
   15 |         printf("和为：%y1,积为：%y2,余为：%y3");
      |                        ^
foo.c:15:34: warning: unknown conversion type character 'y' in format [-Wformat=]
   15 |         printf("和为：%y1,积为：%y2,余为：%y3");
      |                                  ^
foo.c:15:44: warning: unknown conversion type character 'y' in format [-Wformat=]
   15 |         printf("和为：%y1,积为：%y2,余为：%y3");
      |                                            ^
foo.c:4:16: warning: unused variable 's' [-Wunused-variable]
    4 |         double s;
      |                ^
foo.c:3:22: warning: variable 'y2' set but not used [-Wunused-but-set-variable]
    3 |         int x1,x2,y1,y2,y3;
      |                      ^~
foo.c:3:19: warning: variable 'y1' set but not used [-Wunused-but-set-variable]
    3 |         int x1,x2,y1,y2,y3;
      |                   ^~

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