foo.c:2:1: warning: return type defaults to 'int' [-Wimplicit-int]
 main()
 ^~~~
foo.c: In function 'main':
foo.c:8:18: error: array subscript is not an integer
   scanf("%f ",str[i]);
                  ^
foo.c:13:12: error: array subscript is not an integer
   if(b==str[i])
            ^
foo.c:4:8: warning: variable 'str' set but not used [-Wunused-but-set-variable]
  float str[100],i,a,b;
        ^~~
foo.c:5:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%f",&a);
  ^~~~~~~~~~~~~~
foo.c:10:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%f",&b);
  ^~~~~~~~~~~~~~

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