Language: C

char s[];main(){double*q,b;for(q=a+9;~scanf("%s",s);getchar()<14&&printf("%f\n",*q)){!sscanf(s,"%lf",q+1)?b=*q--,*q=*s-47?*s-42?*s-45?*q+b:*q-b:*q*b:*q/b:*++q;}}

Compiler output:
main.c:1:10: error: return type defaults to 'int' [-Wimplicit-int]
    1 | char s[];main(){double*q,b;for(q=a+9;~scanf("%s",s);getchar()<14&&printf("%f\n",*q)){!sscanf(s,"%lf",q+1)?b=*q--,*q=*s-47?*s-42?*s-45?*q+b:*q-b:*q*b:*q/b:*++q;}}
      |          ^~~~
main.c: In function 'main':
main.c:1:34: error: 'a' undeclared (first use in this function)
    1 | char s[];main(){double*q,b;for(q=a+9;~scanf("%s",s);getchar()<14&&printf("%f\n",*q)){!sscanf(s,"%lf",q+1)?b=*q--,*q=*s-47?*s-42?*s-45?*q+b:*q-b:*q*b:*q/b:*++q;}}
      |                                  ^
main.c:1:34: note: each undeclared identifier is reported only once for each function it appears in
main.c:1:39: error: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
    1 | char s[];main(){double*q,b;for(q=a+9;~scanf("%s",s);getchar()<14&&printf("%f\n",*q)){!sscanf(s,"%lf",q+1)?b=*q--,*q=*s-47?*s-42?*s-45?*q+b:*q-b:*q*b:*q/b:*++q;}}
      |                                       ^~~~~
main.c:1:1: note: include '<stdio.h>' or provide a declaration of 'scanf'
  +++ |+#include <stdio.h>
    1 | char s[];main(){double*q,b;for(q=a+9;~scanf("%s",s);getchar()<14&&printf("%f\n",*q)){!sscanf(s,"%lf",q+1)?b=*q--,*q=*s-47?*s-42?*s-45?*q+b:*q-b:*q*b:*q/b:*++q;}}
main.c:1:39: warning: incompatible implicit declaration of built-in function 'scanf' [-Wbuiltin-declaration-mismatch]
    1 | char s[];main(){double*q,b;for(q=a+9;~scanf("%s",s);getchar()<14&&printf("%f\n",*q)){!sscanf(s,"%lf",q+1)?b=*q--,*q=*s-47?*s-42?*s-45?*q+b:*q-b:*q*b:*q/b:*++q;}}
      |                                       ^~~~~
main.c:1:39: note: include '<stdio.h>' or provide a declaration of 'scanf'
main.c:1:53: error: implicit declaration of function 'getchar' [-Wimplicit-function-declaration]
    1 | char s[];main(){double*q,b;for(q=a+9;~scanf("%s",s);getchar()<14&&printf("%f\n",*q)){!sscanf(s,"%lf",q+1)?b=*q--,*q=*s-47?*s-42?*s-45?*q+b:*q-b:*q*b:*q/b:*++q;}}
      |                                                     ^~~~~~~
main.c:1:53: note: 'getchar' is defined in header '<stdio.h>'; this is probably fixable by adding '#include <stdio.h>'
main.c:1:67: error: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
    1 | char s[];main(){double*q,b;for(q=a+9;~scanf("%s",s);getchar()<14&&printf("%f\n",*q)){!sscanf(s,"%lf",q+1)?b=*q--,*q=*s-47?*s-42?*s-45?*q+b:*q-b:*q*b:*q/b:*++q;}}
      |                                                                   ^~~~~~
main.c:1:67: note: include '<stdio.h>' or provide a declaration of 'printf'
main.c:1:67: warning: incompatible implicit declaration of built-in function 'printf' [-Wbuiltin-declaration-mismatch]
main.c:1:67: note: include '<stdio.h>' or provide a declaration of 'printf'
main.c:1:87: error: implicit declaration of function 'sscanf' [-Wimplicit-function-declaration]
    1 | char s[];main(){double*q,b;for(q=a+9;~scanf("%s",s);getchar()<14&&printf("%f\n",*q)){!sscanf(s,"%lf",q+1)?b=*q--,*q=*s-47?*s-42?*s-45?*q+b:*q-b:*q*b:*q/b:*++q;}}
      |                                                                                       ^~~~~~
main.c:1:87: note: include '<stdio.h>' or provide a declaration of 'sscanf'
main.c:1:87: warning: incompatible implicit declaration of built-in function 'sscanf' [-Wbuiltin-declaration-mismatch]
main.c:1:87: note: include '<stdio.h>' or provide a declaration of 'sscanf'
main.c: At top level:
main.c:1:6: warning: array 's' assumed to have one element
    1 | char s[];main(){double*q,b;for(q=a+9;~scanf("%s",s);getchar()<14&&printf("%f\n",*q)){!sscanf(s,"%lf",q+1)?b=*q--,*q=*s-47?*s-42?*s-45?*q+b:*q-b:*q*b:*q/b:*++q;}}
      |      ^