foo.c:2:15: error: expected ';', ',' or ')' before '&' token
 void swap(int &d,int &e){
               ^
foo.c: In function 'main':
foo.c:11:3: warning: implicit declaration of function 'swap' [-Wimplicit-function-declaration]
   swap(a,b);
   ^~~~
foo.c:9:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d%d",&a,&b,&c);
  ^~~~~~~~~~~~~~~~~~~~~~~~

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