复杂四则运算

 设计思想：利用ifelse语句多层嵌套做的，程序设计思想简单，比价容易实现，是否有负数用的whlie语句，另外四则运算还是运用switch语句进行实现的，基本思想就是这些。 
  1 #include<iostream.h>
  2 #include<stdlib.h>
  3 #include<time.h>
  4 int main()
  5 {
  6     srand(time(NULL));
  7     int a, b, c,d,f,g,h,p,q,r,s;
  8     cout<<"请输入计算的数值范围(min)：";
  9         cin>>p;
 10     cout<<"请输入计算的数值范围(max)：";
 11         cin>>q;
 12     cout<<"请输入题目数量i= ";
 13         cin>>d;
 14     cout<<"是否需要乘除法1/0 :";
 15         cin>>f;
 16     cout<<"是否需要加入括号1/0:";
 17         cin>>g;
 18     cout<<"是否允许结果有负数1/0:";
 19         cin>>r;
 20 if(r==1)
 21 {
 22     if (f==1)
 23     {
 24         if(g==1)
 25             for(int i = 1; i <= d; i++)
 26             {
 27              a = rand() % (q-p+1)+p;
 28              b = rand() % (q-p+1)+p;
 29              h = rand() % (q-p+1)+p;
 30              c = rand() % 6;
 31                 switch (c)
 32              {
 33             case 0:
 34                 cout<< a << "+" << b << "=" << endl;
 35                 break;
 36             case 1:
 37                 cout<< a << "-" << b << "=" << endl;
 38                 break;
 39             case 2:
 40                 cout<< a << "*" << b << "=" << endl;
 41                 break;
 42             case 3:
 43                 cout<< a << "/" << b << "=" << endl;
 44                 break;
 45             case 4:
 46                 cout<<"("<<a<<"+"<<b<<")"<<"-"<<h<<"="<<endl;
 47                 break;
 48             case 5:
 49                 cout<<"("<<a<<"-"<<b<<")"<<"+"<<h<<"="<<endl;
 50              }
 51             }
 52         else
 53             for(int i = 1; i <= d; i++)
 54             {
 55              a = rand() % (q-p+1)+p;
 56              b = rand() % (q-p+1)+p;
 57              c = rand() % 4;
 58                 switch (c)
 59              {
 60             case 0:
 61                 cout<< a << "+" << b << "=" << endl;
 62                 break;
 63             case 1:
 64                 cout<< a << "-" << b << "=" << endl;
 65                 break;
 66             case 2:
 67                 cout<< a << "*" << b << "=" << endl;
 68                 break;
 69             case 3:
 70                 cout<< a << "/" << b << "=" << endl;
 71                 break;
 72              }
 73             }
 74     }
 75     else
 76         if(g==1)
 77         for(int i = 1; i <= d; i++)
 78         {
 79         a = rand() % (q-p+1)+p;
 80         b = rand() % (q-p+1)+p;
 81         h = rand() % (q-p+1)+p;
 82         c = rand() % 4;
 83         switch (c)
 84         {
 85             case 0:
 86               cout<< a << '+'<< b << "=" << endl;
 87               break;
 88             case 1:
 89               cout<< a << "-" << b << "=" << endl;
 90               break;
 91             case 2:
 92                 cout<<"("<<a<<"+"<<b<<")"<<"-"<<h<<"="<<endl;
 93                 break;
 94             case 3:
 95                 cout<<"("<<a<<"-"<<b<<")"<<"+"<<h<<"="<<endl;
 96         }
 97         }
 98         else
 99             for(int i = 1; i <= d; i++)
100             {
101              a = rand() % (q-p+1)+p;
102              b = rand() % (q-p+1)+p;
103              c = rand() % 2;
104              switch (c)
105              {
106             case 0:
107               cout<< a << "+" << b << "=" << endl;
108               break;
109             case 1:
110               cout<< a << "-" << b << "=" << endl;
111               break;
112              }
113             }
114 }
115 else
116 if (f==1)
117     {
118         if(g==1)
119             for(int i = 1; i <= d; i++)
120             {
121              a = rand() % (q-p+1)+p;
122              b = rand() % (q-p+1)+p;
123              h = rand() % (q-p+1)+p;
124              c = rand() % 6;
125              while (a<b)
126              {
127             a=rand()%100;
128             b=rand()%100;
129              }
130                 switch (c)
131              {
132             case 0:
133                 cout<< a << "+" << b << "=" << endl;
134                 break;
135             case 1:
136                 cout<< a << "-" << b << "=" << endl;
137                 break;
138             case 2:
139                 cout<< a << "*" << b << "=" << endl;
140                 break;
141             case 3:
142                 cout<< a << "/" << b << "=" << endl;
143                 break;
144             case 4:
145                 cout<<"("<<a<<"+"<<b<<")"<<"-"<<h<<"="<<endl;
146                 break;
147             case 5:
148                 cout<<"("<<a<<"-"<<b<<")"<<"+"<<h<<"="<<endl;
149              }
150             }
151         else
152             for(int i = 1; i <= d; i++)
153             {
154              a = rand() % (q-p+1)+p;
155              b = rand() % (q-p+1)+p;
156              c = rand() % 4;
157              while (a<b)
158              {
159             a=rand()%100;
160             b=rand()%100;
161              }
162                 switch (c)
163              {
164             case 0:
165                 cout<< a << "+" << b << "=" << endl;
166                 break;
167             case 1:
168                 cout<< a << "-" << b << "=" << endl;
169                 break;
170             case 2:
171                 cout<< a << "*" << b << "=" << endl;
172                 break;
173             case 3:
174                 cout<< a << "/" << b << "=" << endl;
175                 break;
176              }
177             }
178     }
179     else
180         if(g==1)
181         for(int i = 1; i <= d; i++)
182         {
183         a = rand() % (q-p+1)+p;
184         b = rand() % (q-p+1)+p;
185         h = rand() % (q-p+1)+p;
186         c = rand() % 4;
187          while (a<b)
188              {
189             a=rand()%100;
190             b=rand()%100;
191              }
192         switch (c)
193         {
194             case 0:
195               cout<< a << "+" << b << "=" << endl;
196               break;
197             case 1:
198               cout<< a << "-" << b << "=" << endl;
199               break;
200             case 2:
201                 cout<<"("<<a<<"+"<<b<<")"<<"-"<<h<<"="<<endl;
202                 break;
203             case 3:
204                 cout<<"("<<a<<"-"<<b<<")"<<"+"<<h<<"="<<endl;
205         }
206         }
207         else
208             for(int i = 1; i <= d; i++)
209             {
210              a = rand() % (q-p+1)+p;
211              b = rand() % (q-p+1)+p;
212              c = rand() % 2;
213               while (a<b)
214              {
215             a=rand()%100;
216             b=rand()%100;
217              }
218              switch (c)
219              {
220             case 0:
221               cout<< a << "+" << b << "=" << endl;
222               break;
223             case 1:
224               cout<< a << "-" << b << "=" << endl;
225               break;
226              }
227             }
228         return 0;
229 }
总结：程序比较简单、傻瓜式的。只是用了很多if else语句，这次的程序健壮性很差，因为一开始就这么做了，后来准备用二叉树或者链表之类的改的话自己不太会，时间不够了。。。只能这样了功能实现还是可以的。先交上四则运算1.0版本。等后续会改进的
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原文地址：https://www.cnblogs.com/gaiiiiiiii/p/4331471.html