foo.cc: In function 'int main()':
foo.cc:5:16: warning: unused variable 'c' [-Wunused-variable]
    5 |         double c,s,pi=3.14;
      |                ^
foo.cc:5:18: warning: unused variable 's' [-Wunused-variable]
    5 |         double c,s,pi=3.14;
      |                  ^
foo.cc:5:20: warning: unused variable 'pi' [-Wunused-variable]
    5 |         double c,s,pi=3.14;
      |                    ^~
foo.cc:7:22: warning: 'n' is used uninitialized [-Wuninitialized]
    7 |         for(int i=1;i<=n;i++)
      |                     ~^~~
foo.cc:6:19: note: 'n' was declared here
    6 |         int sum=1,n;
      |                   ^

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