nadesiko, 287 bytes

Result

WA

Duration

721ms

Code [DL]

aは配列
fは配列
i=-2
標準入力取得した時には(s)
t=sを「 」で区切る
i=i+1
もしi=(-1)なら
 f=t
違えば
 a[3*i]=t@0-f@0
 a[3*i+1]=t@1-f@1
 a[3*i+2]=t@2-f@2
 もしi=2なら
  ((a@0*a@4*a@8+a@1*a@5*a@6+a@2*a@3*a@7-a@2*a@4*a@6-a@1*a@3*a@8-a@0*a@5*a@7)/6)と表示

stdin

19 32 35
56 71 11
19 10 86
99 40 02

stdout

stderr

undefined:30
__v0.line=9;__varslist[2]["a"][(parseFloat(3) * parseFloat(__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>:30:82)
    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