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179 lines
5.5 KiB
Markdown
179 lines
5.5 KiB
Markdown
---
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id: 59e09e6d412c5939baa02d16
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title: 实现马尔可夫 (Markov) 算法
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challengeType: 1
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forumTopicId: 302260
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dashedName: execute-a-markov-algorithm
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---
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# --description--
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Markov Concepts are used in machine learning, because of its simple approach in data manipulation. With a set number of `rules` you can manipulate given `data` to create a desired `output`.
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我们事先在背景中添加了：
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The `rules` in the form of nested array, and the `data` in the form of array, too. 以及想要的输出 (`outputs`)。
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规则 (`rules`)：
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```js
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let rules=[
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[
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"A -> apple","B -> bag","S -> shop","T -> the",
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"the shop -> my brother","a never used -> .terminating rule"
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],
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[
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"A -> apple","B -> bag","S -> .shop","T -> the",
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"the shop -> my brother","a never used -> .terminating rule"
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],
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[
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"A -> apple","WWWW -> with","Bgage -> ->.*","B -> bag",
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"->.* -> money","W -> WW","S -> .shop","T -> the",
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"the shop -> my brother","a never used -> .terminating rule"
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],
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[
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"_+1 -> _1+","1+1 -> 11+","1! -> !1",",! -> !+","_! -> _","1*1 -> x,@y","1x -> xX",
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"X, -> 1,1","X1 -> 1X","_x -> _X",",x -> ,X","y1 -> 1y","y_ -> _","1@1 -> x,@y",
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"1@_ -> @_",",@_ -> !_","++ -> +","_1 -> 1","1+_ -> 1","_+_ -> "
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],
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[
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"A0 -> 1B","0A1 -> C01","1A1 -> C11","0B0 -> A01","1B0 -> A11",
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"B1 -> 1B","0C0 -> B01","1C0 -> B11","0C1 -> H01","1C1 -> H11"
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]
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];
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```
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数据 (`data`)：
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```js
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let data=[
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"I bought a B of As from T S.",
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"I bought a B of As from T S.",
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"I bought a B of As W my Bgage from T S.",
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"_1111*11111_",
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"000000A000000"
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];
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```
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输出 (`outputs`)：
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```js
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let outputs=[
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"I bought a bag of apples from my brother.",
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"I bought a bag of apples from T shop.",
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"I bought a bag of apples with my money from T shop.",
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"11111111111111111111",
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"00011H1111000"
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]
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```
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基于马尔可夫算法，使用提供给你的规则 (`rules`) 将数据 (`data`) 更改为想要的输出 (`outputs`) 。
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# --hints--
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`markov` 应该是一个函数。
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```js
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assert(typeof markov === 'function');
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```
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`markov(["A -> apple","B -> bag","S -> shop","T -> the","the shop -> my brother","a never used -> .terminating rule"],"I bought a B of As from T S.")` 应该返回字符串 `I bought a bag of apples from my brother.`。
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```js
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assert.deepEqual(markov(rules[0], datas[0]), outputs[0]);
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```
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`markov(["A -> apple","B -> bag","S -> .shop","T -> the","the shop -> my brother","a never used -> .terminating rule"],"I bought a B of As from T S.")` 应该返回字符串 `I bought a bag of apples from T shop.`。
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```js
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assert.deepEqual(markov(rules[1], datas[1]), outputs[1]);
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```
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`markov(["A -> apple","WWWW -> with","Bgage -> ->.*","B -> bag","->.* -> money","W -> WW","S -> .shop","T -> the","the shop -> my brother","a never used -> .terminating rule"],"I bought a B of As W my Bgage from T S.")` 应该返回字符串 `I bought a bag of apples with my money from T shop.`。
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```js
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assert.deepEqual(markov(rules[2], datas[2]), outputs[2]);
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```
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`markov(["_+1 -> _1+","1+1 -> 11+","1! -> !1",",! -> !+","_! -> _","1*1 -> x,@y","1x -> xX","X, -> 1,1","X1 -> 1X","_x -> _X",",x -> ,X","y1 -> 1y","y_ -> _","1@1 -> x,@y","1@_ -> @_",",@_ -> !_","++ -> +","_1 -> 1","1+_ -> 1","_+_ -> "],"_1111*11111_")` should return the string `11111111111111111111`.
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```js
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assert.deepEqual(markov(rules[3], datas[3]), outputs[3]);
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```
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`markov(["A0 -> 1B","0A1 -> C01","1A1 -> C11","0B0 -> A01","1B0 -> A11","B1 -> 1B","0C0 -> B01","1C0 -> B11","0C1 -> H01","1C1 -> H11"],"")` 应该返回字符串 `00011H1111000`。
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```js
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assert.deepEqual(markov(rules[4], datas[4]), outputs[4]);
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```
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# --seed--
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## --after-user-code--
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```js
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let rules=[["A -> apple","B -> bag","S -> shop","T -> the","the shop -> my brother","a never used -> .terminating rule"],
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["A -> apple","B -> bag","S -> .shop","T -> the","the shop -> my brother","a never used -> .terminating rule"],
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["A -> apple","WWWW -> with","Bgage -> ->.*","B -> bag","->.* -> money","W -> WW","S -> .shop","T -> the","the shop -> my brother","a never used -> .terminating rule"],
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["_+1 -> _1+","1+1 -> 11+","1! -> !1",",! -> !+","_! -> _","1*1 -> x,@y","1x -> xX","X, -> 1,1","X1 -> 1X","_x -> _X",",x -> ,X","y1 -> 1y","y_ -> _","1@1 -> x,@y","1@_ -> @_",",@_ -> !_","++ -> +","_1 -> 1","1+_ -> 1","_+_ -> "],
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["A0 -> 1B","0A1 -> C01","1A1 -> C11","0B0 -> A01","1B0 -> A11","B1 -> 1B","0C0 -> B01","1C0 -> B11","0C1 -> H01","1C1 -> H11"]];
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let datas=["I bought a B of As from T S.",
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"I bought a B of As from T S.",
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"I bought a B of As W my Bgage from T S.",
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"_1111*11111_",
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"000000A000000"];
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let outputs=["I bought a bag of apples from my brother.",
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"I bought a bag of apples from T shop.",
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"I bought a bag of apples with my money from T shop.",
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"11111111111111111111",
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"00011H1111000"]
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```
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## --seed-contents--
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```js
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function markov(rules,data) {
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}
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```
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# --solutions--
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```js
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function markov(rules,data) {
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let pattern = new RegExp("^([^#]*?)\\s+->\\s+(\\.?)(.*)");
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let origData = data;
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let captures = [];
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rules.forEach(function(rule){
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let m = pattern.exec(rule);
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for (let j = 0; j < m.length; j++)
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m[j] = m[j + 1];
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captures.push(m);
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});
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data = origData;
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let copy = data;
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for (let j = 0; j < captures.length; j++) {
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let c = captures[j];
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data = data.replace(c[0], c[2]);
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if (c[1]==".")
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break;
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if (data!=copy) {
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j = -1;
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copy = data;
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}
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}
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return data;
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}
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```
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