1000-输入输出LL(1)语法分析程序

最新推荐文章于 2024-03-29 11:27:33 发布

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最新推荐文章于 2024-03-29 11:27:33 发布

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分类专栏： sicily 文章标签： sicily LL-1 编译原理

本文链接：https://blog.youkuaiyun.com/lichen_yun/article/details/78740265

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本文介绍了一个基于编译原理的代码实现示例，该示例通过输入文法符号和表达式，输出对应的产生式矩阵。代码使用了C++语言，并涉及字符串处理、向量操作等功能。

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注:编译原理题目

题目描述

这里写图片描述

代码实现

#include <iostream>
#include <vector>
#include <cstring>
#include <string.h>
#include <iomanip>
using namespace std;

#define MAXSIZE 1000

string result[MAXSIZE][MAXSIZE];
string expr[MAXSIZE];
vector<char> vt; 
vector<char> vn; 

int findrow(char ch) {
    int n = vn.size();
    for (int i = 0; i < n; ++i) {
        if (vn[i] == ch)
            return i;
    }
}
int findcol(char ch) {
    int n = vt.size();
    for (int i = 0; i < n; ++i) {
        if (vt[i] == ch)
            return i;
    }
}
int main() {
    char start;
    char ch;
    // initialize
    for (int i = 0; i < MAXSIZE; ++i)
        expr[i] = "";
    for (int i = 0; i < MAXSIZE; ++i) {
        for (int j = 0; j < MAXSIZE; ++j) {
            result[i][j] = "";
        }
    }
    //  vt and vn
    int vnnum, vtnum, exprnum, pronum;
    cin >> start;
    cin >> vnnum;
    for (int i = 0; i < vnnum; ++i) {
        cin >> ch;
        vn.push_back(ch);
    }
    cin >> vtnum;
    for (int i = 0; i < vtnum; ++i) {
        cin >> ch;
        vt.push_back(ch);
    }
    vt.push_back('#');
    vtnum++;
    //  expression
    cin >> exprnum;
    int seq;
    string str;
    for (int i = 0; i < exprnum; ++i) {
        cin >> seq >> ch >> str;
        expr[seq] = str;
    }
    //  production expression
    char vnchar, vtchar;
    int relseq;
    cin >> pronum;
    for (int i = 0; i < pronum; ++i) {
        cin >> seq >> vnchar >> vtchar >> relseq;
        result[findrow(vnchar)][findcol(vtchar)] = expr[relseq];
    }
    //  print the result 
    int widthOccupy = 5;
    cout << setw(widthOccupy) << ' ';
    for (int i = 0; i < vtnum; ++i) 
        cout << setw(widthOccupy) << vt[i];
    cout << endl;
    for (int i = 0; i < vnnum; ++i) {
        cout << setw(widthOccupy) << vn[i];
        for (int j = 0; j < vtnum; ++j) {
            cout << setw(widthOccupy) << result[findrow(vn[i])][findcol(vt[j])];
        }
        cout << endl;
    }
    return 0;
}