NFA转换为等价的DFA

Posted 2021-07-25 coder斌

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NFA转换为等价的DFA

- NFA转换为等价的DFA
- 总结

NFA转换为等价的DFA

明天要进行实验报告的答辩，四个实验，我选择的一个实验报告关于：NFA转换为等价的DFA。实验报告上面的代码，第一眼看得我心里直发麻：What the hell is this？

哎，那就自己写一个吧！

运行环境：NodeJS
目录结构：

代码展示
注意：因为我在敲代码的时候，没有 ε这个符号，我就用 -代替了，这不影响结果

conversionArc.js

function moveIAndNum(graph, arrList, edge) {
    const moveList = [];
    for (let i = 0; i < arrList.length; i++) {
        const currentEdgs = graph.dictonary.get(arrList[i]);
        for (index in currentEdgs) {
            if (currentEdgs[index] === edge) {
                moveList.push(index)
            }
        }
    }
    return moveList
}

module.exports = {
    moveIAndNum
}

numClosure.js

 function getNumClosure(graph, num) {
     const newArr = [];
     for (let i = 0; i < num.length; i++) {
         newArr.push(num[i]);
         getNextNum(graph, num[i], newArr);
     }
     return newArr
 }
 // 递归求解 状态集合I- 闭包
 function getNextNum(graph, num, arrList) {
     const startNode = graph.getEdges(num);
     for (item in startNode) {
         if (startNode[item] === '-') {
             arrList.push(item);
             getNextNum(graph, item, arrList)
         }
     }
 }

 module.exports = {
     getNumClosure
 }

subsetConstruction.js

const {
    getNumClosure
} = require('./numClosure');
const {
    moveIAndNum
} = require('./conversionArc')
const {
    getListExiste
} = require('../utils/utils')


// 构造子集
function getSubsetConst(graph, startNum, constantList) {
    const subsetList = []; // 存放一个个子集
    const startList = [startNum];
    const startSubset = getNumClosure(graph, startList);
    subsetList.push(startSubset);
    for (let flag = 0; flag < subsetList.length; flag++) {
        for (let i = 0; i < constantList.length; i++) {
            const newList = getNumClosure(graph, moveIAndNum(graph, subsetList[flag], constantList[i]));
            const isExiste = getListExiste(newList, subsetList);
            if (isExiste === -1) {
                subsetList.push(newList);
            }
        }
    }
    const resultList = []; // 存放子集对应的结果
    for (let j = 0; j < subsetList.length; j++) {
        for (let i = 0; i < constantList.length; i++) {
            const newList = getNumClosure(graph, moveIAndNum(graph, subsetList[j], constantList[i]));
            const isExiste = getListExiste(newList, subsetList);
            if (isExiste !== -1) {
                const tempObj = {};
                tempObj.from = j;
                tempObj.route = constantList[i];
                tempObj.to = isExiste;
                resultList.push(tempObj);
            }
        }
    }
    return resultList;
}

module.exports = {
    getSubsetConst
}

utils.js

// 比较两个数组内容是否全等
function compareTwoList(list1, list2) {
    const listlength1 = list1.length;
    const listlength2 = list2.length;
    if (listlength1 != listlength2) {
        return false
    }
    for (let i = 0; i < listlength1; i++) {
        let flag = false;
        for (let j = 0; j < listlength2; j++) {
            if (list1[i] === list2[j]) {
                flag = true;
            }
        }
        if (!flag) {
            return false
        }
    }
    return true
}
// 一个数在另一个数组里面是否存在
function getListExiste(decimalArray, largeArray) {
    for (let i = 0; i < largeArray.length; i++) {
        const flag = compareTwoList(decimalArray, largeArray[i]);
        if (flag) {
            return i
        }
    }
    return -1

}

module.exports = {
    getListExiste
}

main.js入口 js 文件

const graph = require('./test/data');

const {
    getSubsetConst
} = require('./controller/subsetConstruction');
const constantList = ['a', 'b'];


console.log(getSubsetConst(graph, '0', constantList));