foo.cc: In function 'int main()':
foo.cc:9:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a1[i]);
   ~~~~~^~~~~~~~~~~~~~
foo.cc:12:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a2[i]);
   ~~~~~^~~~~~~~~~~~~~
foo.cc:15:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a3[i]);
   ~~~~~^~~~~~~~~~~~~~
foo.cc: In function 'void setl(int*, int, int*, int)':
foo.cc:31:8: warning: 't' may be used uninitialized in this function [-Wmaybe-uninitialized]
    x[k]=t;k++;
    ~~~~^~

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