foo.cc: In function 'int main()':
foo.cc:6:14: warning: right operand of comma operator has no effect [-Wunused-value]
    6 |   cin>>a ,b ,c ;
      |              ^
foo.cc:6:16: warning: right operand of comma operator has no effect [-Wunused-value]
    6 |   cin>>a ,b ,c ;
      |                ^
foo.cc:7:11: warning: 'b' is used uninitialized [-Wuninitialized]
    7 |   d=a*0.2+b*0.2+c*0.6;
      |           ^
foo.cc:5:11: note: 'b' was declared here
    5 |   float a,b,c,d;
      |           ^
foo.cc:7:17: warning: 'c' is used uninitialized [-Wuninitialized]
    7 |   d=a*0.2+b*0.2+c*0.6;
      |                 ^
foo.cc:5:13: note: 'c' was declared here
    5 |   float a,b,c,d;
      |             ^

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