{
  "schema": "wai.quantum.exercise/1",
  "id": "bit-order",
  "translations": { "zh-CN": "machine-assisted: to be reviewed by a fluent reader before it is advertised" },
  "title": { "en": "Reading the bits", "zh-CN": "读懂比特的顺序" },
  "task": {
    "en": "Two qubits, measured into c. Make the outcome 10 every time: c[1] is 1 and c[0] is 0.",
    "zh-CN": "两个量子比特，测量到 c 中。让结果每次都是 10：c[1] 为 1，c[0] 为 0。"
  },
  "starter": [
    "OPENQASM 3.0;",
    "include \"stdgates.inc\";",
    "qubit[2] q;",
    "bit[2] c;",
    "// your gates here",
    "c = measure q;"
  ],
  "intent": { "distribution": { "10": 1.0 } },
  "hints": {
    "en": [
      "An outcome is written with the highest bit first: in 10, the 1 is c[1].",
      "c = measure q writes q[0] into c[0] and q[1] into c[1]. Which qubit must end in |1⟩?"
    ],
    "zh-CN": [
      "结果按最高位在前的顺序书写：在 10 中，1 是 c[1]。",
      "c = measure q 把 q[0] 写入 c[0]，把 q[1] 写入 c[1]。哪个量子比特最后必须处于 |1⟩？"
    ]
  },
  "reference": [
    "OPENQASM 3.0;",
    "include \"stdgates.inc\";",
    "qubit[2] q;",
    "bit[2] c;",
    "x q[1];",
    "c = measure q;"
  ],
  "wrong": [
    {
      "fails": "intent",
      "note": "the flip on q[0] gives 01, the lowest bit",
      "qasm": ["OPENQASM 3.0;", "include \"stdgates.inc\";", "qubit[2] q;", "bit[2] c;", "x q[0];", "c = measure q;"]
    }
  ]
}