Language: C

double c,*p=&c;main(){for(;~scanf("%lf",p)?p++:!printf("%f\n",hypot(*c-c[2],c[1]-*p)););exit(0);}//////

Compiler output:
main.c:1:16: error: return type defaults to 'int' [-Wimplicit-int]
    1 | double c,*p=&c;main(){for(;~scanf("%lf",p)?p++:!printf("%f\n",hypot(*c-c[2],c[1]-*p)););exit(0);}//////
      |                ^~~~
main.c: In function 'main':
main.c:1:29: error: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
    1 | double c,*p=&c;main(){for(;~scanf("%lf",p)?p++:!printf("%f\n",hypot(*c-c[2],c[1]-*p)););exit(0);}//////
      |                             ^~~~~
main.c:1:1: note: include '<stdio.h>' or provide a declaration of 'scanf'
  +++ |+#include <stdio.h>
    1 | double c,*p=&c;main(){for(;~scanf("%lf",p)?p++:!printf("%f\n",hypot(*c-c[2],c[1]-*p)););exit(0);}//////
main.c:1:29: warning: incompatible implicit declaration of built-in function 'scanf' [-Wbuiltin-declaration-mismatch]
    1 | double c,*p=&c;main(){for(;~scanf("%lf",p)?p++:!printf("%f\n",hypot(*c-c[2],c[1]-*p)););exit(0);}//////
      |                             ^~~~~
main.c:1:29: note: include '<stdio.h>' or provide a declaration of 'scanf'
main.c:1:49: error: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
    1 | double c,*p=&c;main(){for(;~scanf("%lf",p)?p++:!printf("%f\n",hypot(*c-c[2],c[1]-*p)););exit(0);}//////
      |                                                 ^~~~~~
main.c:1:49: note: include '<stdio.h>' or provide a declaration of 'printf'
main.c:1:49: warning: incompatible implicit declaration of built-in function 'printf' [-Wbuiltin-declaration-mismatch]
main.c:1:49: note: include '<stdio.h>' or provide a declaration of 'printf'
main.c:1:63: error: implicit declaration of function 'hypot' [-Wimplicit-function-declaration]
    1 | double c,*p=&c;main(){for(;~scanf("%lf",p)?p++:!printf("%f\n",hypot(*c-c[2],c[1]-*p)););exit(0);}//////
      |                                                               ^~~~~
main.c:1:1: note: include '<math.h>' or provide a declaration of 'hypot'
  +++ |+#include <math.h>
    1 | double c,*p=&c;main(){for(;~scanf("%lf",p)?p++:!printf("%f\n",hypot(*c-c[2],c[1]-*p)););exit(0);}//////
main.c:1:63: warning: incompatible implicit declaration of built-in function 'hypot' [-Wbuiltin-declaration-mismatch]
    1 | double c,*p=&c;main(){for(;~scanf("%lf",p)?p++:!printf("%f\n",hypot(*c-c[2],c[1]-*p)););exit(0);}//////
      |                                                               ^~~~~
main.c:1:63: note: include '<math.h>' or provide a declaration of 'hypot'
main.c:1:69: error: invalid type argument of unary '*' (have 'double')
    1 | double c,*p=&c;main(){for(;~scanf("%lf",p)?p++:!printf("%f\n",hypot(*c-c[2],c[1]-*p)););exit(0);}//////
      |                                                                     ^~
main.c:1:73: error: subscripted value is neither array nor pointer nor vector
    1 | double c,*p=&c;main(){for(;~scanf("%lf",p)?p++:!printf("%f\n",hypot(*c-c[2],c[1]-*p)););exit(0);}//////
      |                                                                         ^
main.c:1:78: error: subscripted value is neither array nor pointer nor vector
    1 | double c,*p=&c;main(){for(;~scanf("%lf",p)?p++:!printf("%f\n",hypot(*c-c[2],c[1]-*p)););exit(0);}//////
      |                                                                              ^
main.c:1:89: error: implicit declaration of function 'exit' [-Wimplicit-function-declaration]
    1 | double c,*p=&c;main(){for(;~scanf("%lf",p)?p++:!printf("%f\n",hypot(*c-c[2],c[1]-*p)););exit(0);}//////
      |                                                                                         ^~~~
main.c:1:1: note: include '<stdlib.h>' or provide a declaration of 'exit'
  +++ |+#include <stdlib.h>
    1 | double c,*p=&c;main(){for(;~scanf("%lf",p)?p++:!printf("%f\n",hypot(*c-c[2],c[1]-*p)););exit(0);}//////
main.c:1:89: warning: incompatible implicit declaration of built-in function 'exit' [-Wbuiltin-declaration-mismatch]
    1 | double c,*p=&c;main(){for(;~scanf("%lf",p)?p++:!printf("%f\n",hypot(*c-c[2],c[1]-*p)););exit(0);}//////
      |                                                                                         ^~~~
main.c:1:89: note: include '<stdlib.h>' or provide a declaration of 'exit'