foo.c:1:9: error: #include expects "FILENAME" or <FILENAME>
    1 | #include
      |         ^
foo.c:2:9: error: #include expects "FILENAME" or <FILENAME>
    2 | #include
      |         ^
foo.c:4:1: warning: return type defaults to 'int' [-Wimplicit-int]
    4 | main()
      | ^~~~
foo.c: In function 'main':
foo.c:7:1: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
    7 | printf("请输入年 月 日(按顺序,中间用空格隔开)：");
      | ^~~~~~
foo.c:7:1: warning: incompatible implicit declaration of built-in function 'printf'
foo.c:1:1: note: include '<stdio.h>' or provide a declaration of 'printf'
  +++ |+#include <stdio.h>
    1 | #include
foo.c:8:1: warning: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
    8 | scanf("%d%d%d",&year,&month,&day);
      | ^~~~~
foo.c:8:1: warning: incompatible implicit declaration of built-in function 'scanf'
foo.c:8:1: note: include '<stdio.h>' or provide a declaration of 'scanf'
foo.c:35:1: warning: implicit declaration of function 'system' [-Wimplicit-function-declaration]
   35 | system("pause"); //按任意键继续...
      | ^~~~~~

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