1 #include "iostream"
2 #include "cstring"
3 #include "cstdlib"
4 #include "stack"
5 #include "cmath"
6 #define maxsize 100
7 using namespace std;
8 char str[100];
9 int zhipai[20]={0};
10 int length;
11 char expression[100];
12 class symbol {
13 public:
14 void solve();
15 private:
16 void change();
17 int Calculate();
18 void DoOperator(char op);
19 stack<int> s;
20 };
21
22 void symbol ::DoOperator(char op){
23 double left=0,right=0;
24 switch(op){
25 case ‘|‘:s.push(left||right);break;
26 case ‘&‘:s.push(left&&right);break;
27 case ‘>‘:s.push(!left||right);break;
28 case ‘!‘:s.push((!right)&&left);break;
29 case ‘=‘:s.push(left==right);break;
30 }
31
32 }
33 void symbol ::change()
34 {
35 int k=0;
36 int flag=1;
37 int count=0;
38 for(int i=0;i<pow(2.0,count);i++)
39 {
40 k=1;
41 for(int m=0;m<length;m++)
42 {
43 if(isalpha(str[m]))
44 {
45 if(flag==1)
46 {
47 if(zhipai[k]==0)
48 expression[m]=‘0‘;
49 else
50 expression[m]=‘1‘;
51 k++;
52 }
53 else
54 expression[m]=‘0‘;
55 flag=1;
56 for(int t=m;t>=0;t--)
57 {
58
59 if((str[m+1]==str[t])&&isalpha(str[m+1])&&isalpha(str[t]))
60 flag=0;
61 }
62 }
63 else
64 expression[m]=str[m];
65 }
66 for(int t=0;t<length;t++)
67 {
68 for(int j=t;j<length;j++)
69 {
70 if(str[t]==str[j])
71 {
72 expression[j]=expression[t];
73 }
74 }
75 }
76 }
77 }
78 void plus(int a[],int q)
79 {
80 a[q]=a[q]+1;
81 for(int i=q;a[i]==2;i--)
82 {
83 a[i]=0;
84 a[i-1]=a[i-1]+1;
85 }
86 }
87 int isp(char ch) //联结词的栈内优先级
88 {
89 switch(ch){
90 case ‘#‘:return 0;break;
91 case ‘(‘:return 1;break;
92 case ‘!‘:return 10;break;
93 case ‘=‘:return 9;break;
94 case ‘&‘:return 7;break;
95 case ‘|‘:return 5;break;
96 case ‘>‘:return 3;break;
97 case ‘)‘:return 12;break;
98 default:return -1;break;
99 }
100 }
101 int icp(char ch) //联结词的栈外优先级
102 {
103 switch(ch){
104 case ‘#‘:return 0;break;
105 case ‘(‘:return 12;break;
106 case ‘!‘:return 11;break;
107 case ‘=‘:return 8;break;
108 case ‘&‘:return 6;break;
109 case ‘|‘:return 4;break;
110 case ‘>‘:return 2;break;
111 case ‘)‘:return 1;break;
112 default:return -1;break;
113 }
114 }
115 int symbol ::Calculate()
116 {
117 stack<char> h;
118 char ch,y;
119 h.push(‘#‘);
120 for(int temp=0;temp<length-1;temp++){
121 ch=expression[temp];
122 if(isdigit(ch))
123 {
124 if(ch==‘0‘)
125 s.push(0);
126 else
127 s.push(1);
128 }
129 else if(ch==‘)‘)
130 {
131 for(y=h.top(),h.pop();y!=‘(‘;y=h.top(),h.pop()){
132 DoOperator(y);}
133 }
134 else{
135 if(ch==‘!‘)
136 {
137 s.push(1);
138 }
139 for(y=h.top(),h.pop();isp(y)>icp(ch);y=h.top(),h.pop())
140 DoOperator(y);
141 h.push(y);
142 h.push(ch);
143 }
144 }
145 while(h.size()!=1){
146 y=h.top();
147 h.pop();
148 DoOperator(y);
149 }
150 cout <<s.top()<<endl;
151 return s.top();
152 }
153
154 void symbol::solve()
155 {
156 cout<<"请输入命题逻辑表达式："<<endl;
157 cout<<"（|:或运算，&:与运算，!非运算，>蕴涵运算，=等价运算，以#结尾）"<<endl;
158 cout<<""<<endl;
159 int flag=1;
160 int count=0;
161 cin >>str;
162 length=strlen(str);
163 if(str[length-1]!=‘#‘)
164 {
165 cout<<"未以#结尾,重新输入!"<<endl;
166 system("pause");
167 exit(0);
168 }
169 char bianyuan[100];
170 for(int i=0;i<length;i++)
171 {
172 if(isalpha(str[i])&&(flag==1))
173 {
174 bianyuan[count]=str[i];count++;
175 }
176 flag=1;
177 for(int k=0;k<count;k++)
178 {
179 if(bianyuan[k]==str[i+1])flag=0;
180 }
181 }
182 if(count==0)
183 {
184 cout<<"无命题变元,重新输入!"<<endl;
185 solve();
186 }
187 cout<<"真值表(用0代替F,用1代替T):" <<endl;
188
189 for(int w=0;w<count;w++)
190 cout<<bianyuan[w]<<‘ ‘;
191 cout<<"result"<<endl;
192 int* truth=new int[pow(2.0,count)];
193 stack<char> xh1;
194 xh1.push(‘(‘);
195 stack<char> xh2;
196 stack<char> hx1;
197 hx1.push(‘(‘);
198 stack<char> hx2;
199 for(int r=0;r<pow(2.0,count);r++)
200 {
201 for(int j=1;j<=count;j++)
202 {cout<<zhipai[j]<<‘ ‘;}
203 change();
204 truth[r]=Calculate();
205 if(truth[r]==1)
206 {
207 for(int t=0;t<count;t++)
208 {
209 if(zhipai[t+1]==1)
210 {
211 xh1.push(bianyuan[t]);
212 xh1.push(‘&‘);
213 }
214 else
215 {
216 xh1.push(‘!‘);
217 xh1.push(bianyuan[t]);
218 xh1.push(‘&‘);
219 }
220 }
221 xh1.pop();
222 xh1.push(‘)‘);
223 xh1.push(‘|‘);
224 xh1.push(‘(‘);
225 }
226 if(truth[r]==0)
227 {
228 for(int c=0;c<count;c++)
229 {
230 if(zhipai[c+1]==1)
231 {
232 hx1.push(bianyuan[c]);
233 hx1.push(‘|‘);
234 }
235 else
236 {
237 hx1.push(‘!‘);
238 hx1.push(bianyuan[c]);
239 hx1.push(‘|‘);
240 }
241 }
242 hx1.pop();
243 hx1.push(‘)‘);
244 hx1.push(‘&‘);
245 hx1.push(‘(‘);
246 }
247 plus(zhipai,count);
248 }
249 cout<<"析合范式为:";
250 if(xh1.size()==1)
251 cout<<"无析合范式,此表达式为矛盾式";
252 else{
253 xh1.pop();
254 xh1.pop();
255 while(xh1.size()!=0)
256 {
257 xh2.push(xh1.top());
258 xh1.pop();
259 }
260 while(xh2.size()!=0)
261 {
262 cout<<xh2.top();
263 xh2.pop();
264 }
265 }
266 cout<<endl;
267 cout<<"合析范式为:";
268 if(hx1.size()==1)
269 cout<<"无合析范式,此表达式为重言式";
270 else{
271 hx1.pop();
272 hx1.pop();
273 while(hx1.size()!=0)
274 {
275 hx2.push(hx1.top());
276 hx1.pop();
277 }
278 while(hx2.size()!=0)
279 {
280 cout<<hx2.top();
281 hx2.pop();
282 }
283 }
284 cout<<endl;
285 }
286 void main()
287 {
288
289 symbol a;
290 a.solve();
291 system("pause");
292 }
时间： 2024-10-07 03:25:25