一、程序介绍
本次我和2152524同学结对编程完成的程序是“300道四则运算练习题”，本次程序开发的难点在于2个运算符的各4种形态也即共16种组合方式。我们采用最传统的方式——穷举法，将十六种组合用switch函数一字排开，一个个去输出结果。
二、程序源码
1 #include<iostream>
2 using namespace std;
3
4 int Plus(int a,int b) {
5 return (a + b);
6 }
7
8 int Minus(int a, int b) {
9 return (a - b);
10 }
11
12 int Multiple(int a, int b) {
13 return (a * b);
14 }
15
16 int Divide(int a, int b) {
17 return (a / b);
18 }
19
20 char operatorCreate() {
21 int a;
22 char c;
23 a = rand() % 4 + 1;
24 switch (a)
25 {
26 case 1: c = '+'; break;
27 case 2: c = '-'; break;
28 case 3: c = '*'; break;
29 case 4: c = '/'; break;
30 default:
31 break;
32 }
33
34 return c;
35 }
36
37 int plusPlusCreate(int i,char c1,char c2) {
38 int x1, x2, x3;
39 int temp;
40 x1 = rand() % 100 + 1;
41 x2 = rand() % 100 + 1;
42 x3 = rand() % 100 + 1;
43 cout << i << endl << x1 << c1 << x2 << c2 << x3 << "=" << endl;
44 temp = Plus(Plus(x1, x2), x3);
45 return temp;
46 }
47
48 int plusMinusCreate(int i, char c1, char c2) {
49 int x1, x2, x3;
50 int temp;
51 x1 = rand() % 100 + 1;
52 x2 = rand() % 100 + 1;
53 x3 = rand() % 100 + 1;
54 temp = Minus(Plus(x1, x2), x3);
55 return temp;
56 }
57
58 int plusMultipleCreate(int i, char c1, char c2) {
59 int x1, x2, x3;
60 int temp;
61 x1 = rand() % 100 + 1;
62 x2 = rand() % 100 + 1;
63 x3 = rand() % 100 + 1;
64 cout << i << endl << x1 << c1 << x2 << c2 << x3 << "=" << endl;
65 temp = Multiple(Plus(x1, x2), x3);
66 return temp;
67 }
68
69 int plusDivideCreate(int i, char c1, char c2) {
70 int x1, x2, x3;
71 int temp;
72 x1 = rand() % 100 + 1;
73 x2 = rand() % 100 + 1;
74 x3 = rand() % 100 + 1;
75 cout << i << endl << x1 << c1 << x2 << c2 << x3 << "=" << endl;
76 temp = Divide(Plus(x1, x2), x3);
77 return temp;
78 }
79
80 int minusPlusCreate(int i, char c1, char c2) {
81 int x1, x2, x3;
82 int temp;
83 x1 = rand() % 100 + 1;
84 x2 = rand() % 100 + 1;
85 x3 = rand() % 100 + 1;
86 cout << i << endl << x1 << c1 << x2 << c2 << x3 << "=" << endl;
87 temp = Plus(Minus(x1, x2), x3);
88 return temp;
89 }
90
91 int minusMinusCreate(int i, char c1, char c2) {
92 int x1, x2, x3;
93 int temp;
94 x1 = rand() % 100 + 1;
95 x2 = rand() % 100 + 1;
96 x3 = rand() % 100 + 1;
97 cout << i << endl << x1 << c1 << x2 << c2 << x3 << "=" << endl;
98 temp = Minus(Minus(x1, x2), x3);
99 return temp;
100 }
101
102 int minusMultipleCreate(int i, char c1, char c2) {
103 int x1, x2, x3;
104 int temp;
105 x1 = rand() % 100 + 1;
106 x2 = rand() % 100 + 1;
107 x3 = rand() % 100 + 1;
108 cout << i << endl << x1 << c1 << x2 << c2 << x3 << "=" << endl;
109 temp = Multiple(Minus(x1, x2), x3);
110 return temp;
111 }
112
113 int minusDivideCreate(int i, char c1, char c2) {
114 int x1, x2, x3;
115 int temp;
116 x1 = rand() % 100 + 1;
117 x2 = rand() % 100 + 1;
118 x3 = rand() % 100 + 1;
119 cout << i << endl << x1 << c1 << x2 << c2 << x3 << "=" << endl;
120 temp = Divide(Minus(x1, x2), x3);
121 return temp;
122 }
123
124 int multiplePlusCreate(int i, char c1, char c2) {
125 int x1, x2, x3;
126 int temp;
127 x1 = rand() % 100 + 1;
128 x2 = rand() % 100 + 1;
129 x3 = rand() % 100 + 1;
130 cout << i << endl << x1 << c1 << x2 << c2 << x3 << "=" << endl;
131 temp = Plus(Multiple(x1, x2), x3);
132 return temp;
133 }
134
135 int multipleMinusCreate(int i, char c1, char c2) {
136 int x1, x2, x3;
137 int temp;
138 x1 = rand() % 100 + 1;
139 x2 = rand() % 100 + 1;
140 x3 = rand() % 100 + 1;
141 cout << i << endl << x1 << c1 << x2 << c2 << x3 << "=" << endl;
142 temp = Minus(Multiple(x1, x2), x3);
143 return temp;
144 }
145
146 int multipleMultipleCreate(int i, char c1, char c2) {
147 int x1, x2, x3;
148 int temp;
149 x1 = rand() % 100 + 1;
150 x2 = rand() % 100 + 1;
151 x3 = rand() % 100 + 1;
152 cout << i << endl << x1 << c1 << x2 << c2 << x3 << "=" << endl;
153 temp = Multiple(Multiple(x1, x2), x3);
154 return temp;
155 }
156
157 int multipleDivideCreate(int i, char c1, char c2) {
158 int x1, x2, x3;
159 int temp;
160 x1 = rand() % 100 + 1;
161 x2 = rand() % 100 + 1;
162 x3 = rand() % 100 + 1;
163 cout << i << endl << x1 << c1 << x2 << c2 << x3 << "=" << endl;
164 temp = Divide(Multiple(x1, x2), x3);
165 return temp;
166 }
167
168 int dividePlusCreate(int i, char c1, char c2) {
169 int x1, x2, x3;
170 int temp;
171 x1 = rand() % 100 + 1;
172 x2 = rand() % 100 + 1;
173 x3 = rand() % 100 + 1;
174 cout << i << endl << x1 << c1 << x2 << c2 << x3 << "=" << endl;
175 temp = Plus(Divide(x1, x2), x3);
176 return temp;
177 }
178
179 int divideMinusCreate(int i, char c1, char c2) {
180 int x1, x2, x3;
181 int temp;
182 x1 = rand() % 100 + 1;
183 x2 = rand() % 100 + 1;
184 x3 = rand() % 100 + 1;
185 cout << i << endl << x1 << c1 << x2 << c2 << x3 << "=" << endl;
186 temp = Minus(Divide(x1, x2), x3);
187 return temp;
188 }
189
190 int divideMultipleCreate(int i, char c1, char c2) {
191 int x1, x2, x3;
192 int temp;
193 x1 = rand() % 100 + 1;
194 x2 = rand() % 100 + 1;
195 x3 = rand() % 100 + 1;
196 cout << i << endl << x1 << c1 << x2 << c2 << x3 << "=" << endl;
197 temp = Multiple(Divide(x1, x2), x3);
198 return temp;
199 }
200
201 int divideDivideCreate(int i, char c1, char c2) {
202 int x1, x2, x3;
203 int temp;
204 x1 = rand() % 100 + 1;
205 x2 = rand() % 100 + 1;
206 x3 = rand() % 100 + 1;
207 cout << i << endl << x1 << c1 << x2 << c2 << x3 << "=" << endl;
208 temp = Divide(Divide(x1, x2), x3);
209 return temp;
210 }
211
212 int judge(char c1, char c2) {
213 int t = 0;
214 if (c1 == '+' && c2 == '+') t = 1;
215 else if (c1 == '+' && c2 == '-') t = 2;
216 else if (c1 == '+' && c2 == '*') t = 3;
217 else if (c1 == '+' && c2 == '/') t = 4;
218 else if (c1 == '-' && c2 == '+') t = 5;
219 else if (c1 == '-' && c2 == '-') t = 6;
220 else if (c1 == '-' && c2 == '*') t = 7;
221 else if (c1 == '-' && c2 == '/') t = 8;
222 else if (c1 == '*' && c2 == '+') t = 9;
223 else if (c1 == '*' && c2 == '-') t = 10;
224 else if (c1 == '*' && c2 == '*') t = 11;
225 else if (c1 == '*' && c2 == '/') t = 12;
226 else if (c1 == '/' && c2 == '+') t = 13;
227 else if (c1 == '/' && c2 == '-') t = 14;
228 else if (c1 == '/' && c2 == '*') t = 15;
229 else if (c1 == '/' && c2 == '/') t = 16;
230 return t;
231 }
232 void Create() {
233 int t = 0;
234 int i = 1;
235 while (i <= 300) {
236 char c1 = operatorCreate();
237 char c2 = operatorCreate();
238 t = judge(c1, c2);
239 switch (t)
240 {
241 case 1:plusPlusCreate(i, c1, c2); i++; break;
242 case 2:plusMinusCreate(i, c1, c2); i++; break;
243 case 3:plusMultipleCreate(i, c1, c2); i++; break;
244 case 4:plusDivideCreate(i, c1, c2); i++; break;
245 case 5:minusPlusCreate(i, c1, c2); i++; break;
246 case 6:minusMinusCreate(i, c1, c2); i++; break;
247 case 7:minusMultipleCreate(i, c1, c2); i++; break;
248 case 8:minusDivideCreate(i, c1, c2); i++; break;
249 case 9:multiplePlusCreate(i, c1, c2); i++; break;
250 case 10:multipleMinusCreate(i, c1, c2); i++; break;
251 case 11:multipleMultipleCreate(i, c1, c2); i++; break;
252 case 12:multipleDivideCreate(i, c1, c2); i++; break;
253 case 13:dividePlusCreate(i, c1, c2); i++; break;
254 case 14:divideMinusCreate(i, c1, c2); i++; break;
255 case 15:divideMultipleCreate(i, c1, c2); i++; break;
256 case 16:divideDivideCreate(i, c1, c2); i++; break;
257 default:
258 break;
259 }
260 }
261
262 }
263
264 int main() {
265 Create();
266 return 0;
267 }
可以看到最基本的加减乘除运算我们也将它们封装进了函数（PS：这纯属闲的没事找事），此外我们也将上述16个组合中每一个组合都做了输出的函数，使得main函数看起来十分简洁（PS：这其实也是没事找事做）。
三、心得体会
做出这个程序还是比较简单的，我们的程序肯定还有可以优化的地方。在处理更复杂的情况时不可能用的是穷举法，那样会对计算机造成极大的负荷。我们还要不断学习，加油！
标签：case,rand,结对,return,300,四则运算,break,int,char From： https://www.cnblogs.com/Luvletter2517/p/17304650.html