foo.cc: In function 'int main()':
foo.cc:7:26: warning: too many arguments for format [-Wformat-extra-args]
   scanf("%d", &a,"%d",&b );
                          ^
foo.cc:7:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a,"%d",&b );
   ~~~~~^~~~~~~~~~~~~~~~~~~
foo.cc:5:15: warning: 'n' is used uninitialized in this function [-Wuninitialized]
  for(int i=0;i<=n;i++){
              ~^~~

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