foo.c:3:16: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'sort'
 void selection sort(int array[],int length);
                ^~~~
foo.c: In function 'main':
foo.c:6:18: error: invalid initializer
  float score[30]=0;
                  ^
foo.c:10:12: error: 'num' undeclared (first use in this function)
  for(i=0;i<num;i++)
            ^~~
foo.c:10:12: note: each undeclared identifier is reported only once for each function it appears in
foo.c:12:12: warning: format '%lf' expects argument of type 'double *', but argument 2 has type 'float *' [-Wformat=]
   scanf("%lf",&score[i]);
          ~~^  ~~~~~~~~~
          %f
foo.c:7:8: warning: unused variable 'n' [-Wunused-variable]
  int i,n;
        ^
foo.c: At top level:
foo.c:16:16: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'sort'
 void selection sort(int array[],int length)
                ^~~~
foo.c: In function 'main':
foo.c:12:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lf",&score[i]);
   ^~~~~~~~~~~~~~~~~~~~~~

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