Language: C

a,s[];main(c){double*q=s,b;for(;~scanf("%s%c",s,&c);c&2&&printf("%f\n",*q))sscanf(s,"%lf",q+1)-1?a=*s&7,b=*q--,*q=a-7?a-2?*q+=a-5?b:-b:*a*b:*q/b:*++q;}

Compiler output:
main.c:1:1: warning: data definition has no type or storage class
    1 | a,s[];main(c){double*q=s,b;for(;~scanf("%s%c",s,&c);c&2&&printf("%f\n",*q))sscanf(s,"%lf",q+1)-1?a=*s&7,b=*q--,*q=a-7?a-2?*q+=a-5?b:-b:*a*b:*q/b:*++q;}
      | ^
main.c:1:1: error: type defaults to 'int' in declaration of 'a' [-Wimplicit-int]
main.c:1:3: error: type defaults to 'int' in declaration of 's' [-Wimplicit-int]
    1 | a,s[];main(c){double*q=s,b;for(;~scanf("%s%c",s,&c);c&2&&printf("%f\n",*q))sscanf(s,"%lf",q+1)-1?a=*s&7,b=*q--,*q=a-7?a-2?*q+=a-5?b:-b:*a*b:*q/b:*++q;}
      |   ^
main.c:1:7: error: return type defaults to 'int' [-Wimplicit-int]
    1 | a,s[];main(c){double*q=s,b;for(;~scanf("%s%c",s,&c);c&2&&printf("%f\n",*q))sscanf(s,"%lf",q+1)-1?a=*s&7,b=*q--,*q=a-7?a-2?*q+=a-5?b:-b:*a*b:*q/b:*++q;}
      |       ^~~~
main.c: In function 'main':
main.c:1:7: error: type of 'c' defaults to 'int' [-Wimplicit-int]
main.c:1:24: error: initialization of 'double *' from incompatible pointer type 'int *' [-Wincompatible-pointer-types]
    1 | a,s[];main(c){double*q=s,b;for(;~scanf("%s%c",s,&c);c&2&&printf("%f\n",*q))sscanf(s,"%lf",q+1)-1?a=*s&7,b=*q--,*q=a-7?a-2?*q+=a-5?b:-b:*a*b:*q/b:*++q;}
      |                        ^
main.c:1:34: error: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
    1 | a,s[];main(c){double*q=s,b;for(;~scanf("%s%c",s,&c);c&2&&printf("%f\n",*q))sscanf(s,"%lf",q+1)-1?a=*s&7,b=*q--,*q=a-7?a-2?*q+=a-5?b:-b:*a*b:*q/b:*++q;}
      |                                  ^~~~~
main.c:1:1: note: include '<stdio.h>' or provide a declaration of 'scanf'
  +++ |+#include <stdio.h>
    1 | a,s[];main(c){double*q=s,b;for(;~scanf("%s%c",s,&c);c&2&&printf("%f\n",*q))sscanf(s,"%lf",q+1)-1?a=*s&7,b=*q--,*q=a-7?a-2?*q+=a-5?b:-b:*a*b:*q/b:*++q;}
main.c:1:34: warning: incompatible implicit declaration of built-in function 'scanf' [-Wbuiltin-declaration-mismatch]
    1 | a,s[];main(c){double*q=s,b;for(;~scanf("%s%c",s,&c);c&2&&printf("%f\n",*q))sscanf(s,"%lf",q+1)-1?a=*s&7,b=*q--,*q=a-7?a-2?*q+=a-5?b:-b:*a*b:*q/b:*++q;}
      |                                  ^~~~~
main.c:1:34: note: include '<stdio.h>' or provide a declaration of 'scanf'
main.c:1:58: error: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
    1 | a,s[];main(c){double*q=s,b;for(;~scanf("%s%c",s,&c);c&2&&printf("%f\n",*q))sscanf(s,"%lf",q+1)-1?a=*s&7,b=*q--,*q=a-7?a-2?*q+=a-5?b:-b:*a*b:*q/b:*++q;}
      |                                                          ^~~~~~
main.c:1:58: note: include '<stdio.h>' or provide a declaration of 'printf'
main.c:1:58: warning: incompatible implicit declaration of built-in function 'printf' [-Wbuiltin-declaration-mismatch]
main.c:1:58: note: include '<stdio.h>' or provide a declaration of 'printf'
main.c:1:76: error: implicit declaration of function 'sscanf' [-Wimplicit-function-declaration]
    1 | a,s[];main(c){double*q=s,b;for(;~scanf("%s%c",s,&c);c&2&&printf("%f\n",*q))sscanf(s,"%lf",q+1)-1?a=*s&7,b=*q--,*q=a-7?a-2?*q+=a-5?b:-b:*a*b:*q/b:*++q;}
      |                                                                            ^~~~~~
main.c:1:76: note: include '<stdio.h>' or provide a declaration of 'sscanf'
main.c:1:76: warning: incompatible implicit declaration of built-in function 'sscanf' [-Wbuiltin-declaration-mismatch]
main.c:1:76: note: include '<stdio.h>' or provide a declaration of 'sscanf'
main.c:1:83: error: passing argument 1 of 'sscanf' from incompatible pointer type [-Wincompatible-pointer-types]
    1 | a,s[];main(c){double*q=s,b;for(;~scanf("%s%c",s,&c);c&2&&printf("%f\n",*q))sscanf(s,"%lf",q+1)-1?a=*s&7,b=*q--,*q=a-7?a-2?*q+=a-5?b:-b:*a*b:*q/b:*++q;}
      |                                                                                   ^
      |                                                                                   |
      |                                                                                   int *
main.c:1:83: note: expected 'const char *' but argument is of type 'int *'
main.c:1:136: error: invalid type argument of unary '*' (have 'int')
    1 | a,s[];main(c){double*q=s,b;for(;~scanf("%s%c",s,&c);c&2&&printf("%f\n",*q))sscanf(s,"%lf",q+1)-1?a=*s&7,b=*q--,*q=a-7?a-2?*q+=a-5?b:-b:*a*b:*q/b:*++q;}
      |                                                                                                                                        ^~
main.c: At top level:
main.c:1:3: warning: array 's' assumed to have one element
    1 | a,s[];main(c){double*q=s,b;for(;~scanf("%s%c",s,&c);c&2&&printf("%f\n",*q))sscanf(s,"%lf",q+1)-1?a=*s&7,b=*q--,*q=a-7?a-2?*q+=a-5?b:-b:*a*b:*q/b:*++q;}
      |   ^