利用真值表法求取主析取范式以及主合取范式的实现(C++)

代码如下:

#include <iostream>
#include <stack>
#include <string>
#include <vector>
using namespace std;
const int N = 300;
stack<char> s;
stack<char> v;
int seq;
bool vis[N];
bool flag[N];
void dfs(int n);
vector<int> ans_v;
vector<int> ans_vf;void printMenu()
{cout << "代码其实有点不健壮，需要用括号来手动处理优先级!" << endl;cout << "比如:!!!(a&b&c)  要写成!(!(!(a&b&c)))" << endl;cout << "比如:!(a&b)->c 要写成 (!(a&b))>c" << endl;cout << "合取& 析取| 非! 条件> 双条件~ 括号() " << endl;cout << endl;
}void printAns(vector<int> &ans_v, char f, char v)
{for (int i = 0; i < ans_v.size(); i++){cout << f << ans_v[i];if (i != ans_v.size() - 1){cout << v;}}cout << endl;
}void calculator(int n, string &str)
{str = '(' + str + ')';for (int i = 0; i < str.length(); i++){char tmp = str[i];if (tmp >= 'a' && tmp <= 'z'){vis[tmp - 'a'] = true;s.push(tmp);}else if (tmp == '('){v.push(tmp);}else if (tmp == ')'){while (v.top() != '('){s.push(v.top());v.pop();}v.pop();}else{v.push(tmp);}}stack<char>t;while (!s.empty()){t.push(s.top());s.pop();}s = t;stack<char>h(s);while (!h.empty()){cout << h.top();h.pop();}cout << endl;dfs(0);cout << "主合取范式为:" << endl;printAns(ans_v, 'm', '&');cout << "主析取范式为:" << endl;printAns(ans_vf, 'M', '|');}void dfs(int n)
{if (n == 26){stack<char> s_s(s);stack<bool> s_t;while (!s_s.empty()){if (s_s.top() == '&' || s_s.top() == '|' || s_s.top() == '~' || s_s.top() == '>'){if (s_s.top() == '&'){s_s.pop();bool a2 = s_t.top();s_t.pop();bool a1 = s_t.top();s_t.pop();bool ans = a2 && a1;s_t.push(ans);}else if (s_s.top() == '|'){s_s.pop();bool a2 = s_t.top();s_t.pop();bool a1 = s_t.top();s_t.pop();bool ans = a2 || a1;s_t.push(ans);}else if (s_s.top() == '>'){s_s.pop();bool a2 = s_t.top();s_t.pop();bool a1 = s_t.top();s_t.pop();if (a1 == true && a2 == true){s_t.push(true);}else if (a1 == true && a2 == false){s_t.push(false);}else if (a1 == false){s_t.push(true);}}else if (s_s.top() == '~'){s_s.pop();bool a2 = s_t.top();s_t.pop();bool a1 = s_t.top();s_t.pop();if (a1 == a2){s_t.push(true);}else s_t.push(false);}}else if (s_s.top() == '!'){s_s.pop();bool tmp = !s_t.top();s_t.pop();s_t.push(tmp);}else{s_t.push(flag[s_s.top() - 'a']);s_s.pop();}}for (int i = 0; i < 26; i++){if (vis[i]){cout << char(i + 'a') << "=" << flag[i] << " ";}}if (s_t.top()){ans_v.push_back(seq);cout << "ans=true" << endl;}else{ans_vf.push_back(seq);cout << "ans=false" << endl;}seq++;return;}if (vis[n]){for (int i = 0; i <= 1; i++){flag[n] = i;dfs(n + 1);}}else{dfs(n + 1);}}int main()
{int n;string str;printMenu();cout << "请先输入式子含有的变量个数" << endl;cin >> n;cout << "按格式输入式子" << endl;cin >> str;calculator(n, str);return 0;
}