nadesiko, 229 bytes

Result

WA

Duration

697ms

Code [DL]

a=[]f=[]i=-6標準入力取得時には(s)
t=sを" "で区切る
i=i+3もしi<0ならf=t
違えa@i=t@0-f@0
a[i+1]=t@1-f@1
a[i+2]=t@2-f@2もしi=6なら(a@0*(a@4*a@8-a@5*a@7)+a@1*(a@5*a@6-a@3*a@8)+a@2*(a@3*a@7-a@4*a@6))/6と表示

stdin

10 19 90
43 73 04
17 65 03
75 63 97

stdout

stderr

undefined:23
}else {__v0.line=3;__vars["えa"]/*?:3*/[__varslist[2]["i"]] = (parseFloat(__vars["t"][0]) - parseFloat(__varslist[2]["f"][0]));
                                                           ^

TypeError: Cannot set property '0' of undefined
    at eval (eval at _run (/usr/lib/node_modules/nadesiko3/src/nako3.js:149:7), <anonymous>:23:60)
    at Interface.<anonymous> (/usr/lib/node_modules/nadesiko3/src/plugin_node.js:470:9)
    at emitOne (events.js:116:13)
    at Interface.emit (events.js:211:7)
    at Interface._onLine (readline.js:282:10)
    at Interface._normalWrite (readline.js:424:12)
    at ReadStream.ondata (readline.js:141:10)
    at emitOne (events.js:116:13)
    at ReadStream.emit (events.js:211:7)
    at addChunk (_stream_readable.js:263:12)

strace