foo.c: In function 'main':
foo.c:6:9: warning: too many arguments for format [-Wformat-extra-args]
  printf("请输入一位整数n:\n",n);
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.c:7:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ^~~~~~~~~~~~~~
foo.c:6:2: warning: 'n' is used uninitialized in this function [-Wuninitialized]
  printf("请输入一位整数n:\n",n);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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