Java学习十七
今天对自己之前的四则运算进行了再次优化。
这次的优化有三个类，Grade2,Grade3,Grade4这三个类是多重继承关系，以便提高代码的复用性，简化了main()方法。
下面是我的源码
1 import java.util.Scanner; 2 3 //二柱子四则运算 4 public class RanE { 5 static Scanner sc=new Scanner(System.in); 6 public static void main(String[] args) { 7 System.out.println("请选择：1、二年级口算题；2、三年级口算题；3、四年级口算题；4、退出"); 8 int i=sc.nextInt(); 9 switch(i) { 10 case 1:Grade2 s1=new Grade2(); 11 s1.answer(); 12 break; 13 case 2: 14 Grade3 s2=new Grade3(); 15 s2.select(); 16 break; 17 case 3:Grade4 s3=new Grade4(); 18 s3.select1(); 19 break; 20 case 4:System.out.println("谢谢使用！"); 21 System.exit(0); 22 } 23 } 24 }
1 import java.util.ArrayList; 2 import java.util.Random; 3 import java.util.Scanner; 4 5 public class Grade2 { 6 static ArrayList<String> s=new ArrayList<String>(); 7 static int[] m=new int[100]; 8 static int[] n=new int[100]; 9 static int i; 10 static Random r=new Random(); 11 static Scanner sc=new Scanner(System.in); 12 static int num; 13 public static void answer() { 14 double count=0; 15 System.out.print("请输入范围（<=100）："); 16 num=sc.nextInt(); 17 System.out.print("请输入题目数(>30)："); 18 int number=sc.nextInt(); 19 for(i=0;i<2*number;i++) { 20 m[i]=r.nextInt(num)+1; 21 n[i]=r.nextInt(num)+1; 22 for(int j=0;j<i;j++) { 23 if(m[i]==m[j]&&n[i]==n[j]) { 24 m[i]=r.nextInt(num)+1; 25 } 26 } 27 int k=r.nextInt(4)+1; 28 switch(k) { 29 case 0:System.out.println(m[i]+"+"+n[i]+"="); 30 double a=sc.nextInt(); 31 System.out.println("正确答案："+(m[i]+n[i])); 32 if(a!=(m[i]+n[i])) { 33 String e=m[i]+"+"+n[i]+"="; 34 s.add(e); 35 count++; 36 } 37 break; 38 case 1:System.out.println(m[i]+"-"+n[i]+"="); 39 double b=sc.nextInt(); 40 System.out.println("正确答案："+(m[i]-n[i])); 41 if(b!=(m[i]-n[i])) { 42 String e=m[i]+"-"+n[i]+"="; 43 s.add(e); 44 count++; 45 } 46 break; 47 case 2:System.out.println(m[i]+"*"+n[i]+"="); 48 double c=sc.nextInt(); 49 System.out.println("正确答案："+(m[i]*n[i])); 50 if(c!=(m[i]*n[i])) { 51 String e=m[i]+"*"+n[i]+"="; 52 s.add(e); 53 count++; 54 } 55 break; 56 case 3:System.out.println(m[i]+"/"+n[i]+"="); 57 double d=sc.nextInt(); 58 System.out.println("正确答案："+(m[i]/n[i])); 59 if(d!=(m[i]/n[i])) { 60 String e=m[i]+"/"+n[i]+"="; 61 s.add(e); 62 count++; 63 } 64 break; 65 } 66 } 67 System.out.println("正确率："+(100-(count/number)*100)+"%"); 68 System.out.println("错题数目："+count); 69 System.out.println("错题："+s); 70 } 71 72 73 }
1 import java.util.Scanner; 2 public class Grade3 extends Grade2{ 3 static int[] j=new int[100]; 4 static int[] z=new int[100]; 5 static Scanner sc=new Scanner(System.in); 6 public static void select() { 7 System.out.println("请选择操作数：1:2个；2:3个；3:4个"); 8 int i=sc.nextInt(); 9 switch(i) { 10 case 1:answer1(); 11 break; 12 case 2:answer2(); 13 break; 14 case 3:answer3(); 15 break; 16 } 17 } 18 19 public static void answer1() { 20 double count=0; 21 System.out.print("请输入范围（<=100）："); 22 num=sc.nextInt(); 23 System.out.print("请输入题目数(>30)："); 24 int number=sc.nextInt(); 25 for(i=0;i<2*number;i++) { 26 m[i]=r.nextInt(num)+1; 27 n[i]=r.nextInt(num)+1; 28 for(int j=0;j<i;j++) { 29 if(m[i]==m[j]&&n[i]==n[j]) { 30 m[i]=r.nextInt(num)+1; 31 } 32 } 33 int k=r.nextInt(4)+1; 34 switch(k) { 35 case 0:System.out.println(m[i]+"+"+n[i]+"="); 36 double a=sc.nextInt(); 37 System.out.println("正确答案："+(m[i]+n[i])); 38 if(a!=(m[i]+n[i])) { 39 String e=m[i]+"+"+n[i]+"="; 40 s.add(e); 41 count++; 42 } 43 break; 44 case 1:System.out.println(m[i]+"-"+n[i]+"="); 45 double b=sc.nextInt(); 46 System.out.println("正确答案："+(m[i]-n[i])); 47 if(b!=(m[i]-n[i])) { 48 String e=m[i]+"-"+n[i]+"="; 49 s.add(e); 50 count++; 51 } 52 break; 53 case 2:System.out.println(m[i]+"*"+n[i]+"="); 54 double c=sc.nextInt(); 55 System.out.println("正确答案："+(m[i]*n[i])); 56 if(c!=(m[i]*n[i])) { 57 String e=m[i]+"*"+n[i]+"="; 58 s.add(e); 59 count++; 60 } 61 break; 62 case 3:System.out.println(m[i]+"/"+n[i]+"="); 63 double d=sc.nextInt(); 64 System.out.println("正确答案："+(m[i]/n[i])); 65 if(d!=(m[i]/n[i])) { 66 String e=m[i]+"/"+n[i]+"="; 67 s.add(e); 68 count++; 69 } 70 break; 71 } 72 } 73 System.out.println("正确率："+(100-(count/number)*100)+"%"); 74 System.out.println("错题数目："+count); 75 System.out.println("错题："+s); 76 } 77 78 79 public static void answer2() { 80 double count=0; 81 System.out.print("请输入范围（<=1000）："); 82 num=sc.nextInt(); 83 System.out.print("请输入题目数(>30)："); 84 int number=sc.nextInt(); 85 for(i=0;i<2*number;i++) { 86 m[i]=r.nextInt(num)+1; 87 n[i]=r.nextInt(num)+1; 88 j[i]=r.nextInt(num)+1; 89 for(int j=0;j<i;j++) { 90 if(m[i]==m[j]&&n[i]==n[j]) { 91 m[i]=r.nextInt(num)+1; 92 } 93 } 94 int k=r.nextInt(4)+1; 95 switch(k) { 96 case 0:System.out.println(m[i]+"+"+n[i]+"-"+j[i]+"="); 97 double a=sc.nextInt(); 98 System.out.println("正确答案："+(m[i]+n[i]-j[i])); 99 if(a!=(m[i]+n[i])) { 100 String e=m[i]+"+"+n[i]+"-"+j[i]+"="; 101 s.add(e); 102 count++; 103 } 104 break; 105 case 1:System.out.println(j[i]+"*"+m[i]+"-"+n[i]+"="); 106 double b=sc.nextInt(); 107 System.out.println("正确答案："+(j[i]*m[i]-n[i])); 108 if(b!=(m[i]-n[i])) { 109 String e=j[i]+"*"+m[i]+"-"+n[i]+"="; 110 s.add(e); 111 count++; 112 } 113 break; 114 case 2:System.out.println(m[i]+"*"+n[i]+"/"+j[i]+"="); 115 double c=sc.nextInt(); 116 System.out.println("正确答案："+(m[i]*n[i]/j[i])); 117 if(c!=(m[i]*n[i])) { 118 String e=m[i]+"*"+n[i]+"/"+j[i]+"="; 119 s.add(e); 120 count++; 121 } 122 break; 123 case 3:System.out.println(m[i]+"/"+n[i]+"+"+j[i]+"="); 124 double d=sc.nextInt(); 125 System.out.println("正确答案："+(m[i]/n[i]+j[i])); 126 if(d!=(m[i]/n[i])) { 127 String e=m[i]+"/"+n[i]+"+"+j[i]+"="; 128 s.add(e); 129 count++; 130 } 131 break; 132 } 133 } 134 System.out.println("正确率："+(100-(count/number)*100)+"%"); 135 System.out.println("错题数目："+count); 136 System.out.println("错题："+s); 137 } 138 139 public static void answer3() { 140 double count=0; 141 System.out.print("请输入范围（<=1000）："); 142 num=sc.nextInt(); 143 System.out.print("请输入题目数(>30)："); 144 int number=sc.nextInt(); 145 for(i=0;i<2*number;i++) { 146 m[i]=r.nextInt(num)+1; 147 n[i]=r.nextInt(num)+1; 148 j[i]=r.nextInt(num)+1; 149 z[i]=r.nextInt(num)+1; 150 for(int j=0;j<i;j++) { 151 if(m[i]==m[j]&&n[i]==n[j]) { 152 m[i]=r.nextInt(num)+1; 153 } 154 } 155 int k=r.nextInt(4)+1; 156 switch(k) { 157 case 0:System.out.println(z[i]+"*"+m[i]+"+"+n[i]+"-"+j[i]+"="); 158 double a=sc.nextInt(); 159 System.out.println("正确答案："+(z[i]*m[i]+n[i]-j[i])); 160 if(a!=(m[i]+n[i])) { 161 String e=z[i]+"*"+m[i]+"+"+n[i]+"-"+j[i]+"="; 162 s.add(e); 163 count++; 164 } 165 break; 166 case 1:System.out.println(m[i]+"/"+j[i]+"+"+z[i]+"-"+n[i]+"="); 167 double b=sc.nextInt(); 168 System.out.println("正确答案："+(m[i]/j[i]+z[i]-n[i])); 169 if(b!=(m[i]-n[i])) { 170 String e=m[i]+"/"+j[i]+"+"+z[i]+"-"+n[i]+"="; 171 s.add(e); 172 count++; 173 } 174 break; 175 case 2:System.out.println(z[i]+"-"+m[i]+"*"+n[i]+"/"+j[i]+"="); 176 double c=sc.nextInt(); 177 System.out.println("正确答案："+(z[i]-m[i]*n[i]/j[i])); 178 if(c!=(m[i]*n[i])) { 179 String e=z[i]+"-"+m[i]+"*"+n[i]+"/"+j[i]+"="; 180 s.add(e); 181 count++; 182 } 183 break; 184 case 3:System.out.println(j[i]+"-"+m[i]+"/"+"-"+z[i]+n[i]+"="); 185 double d=sc.nextInt(); 186 System.out.println("正确答案："+(m[i]/n[i])); 187 if(d!=(m[i]/n[i])) { 188 String e=m[i]+"/"+n[i]+"="; 189 s.add(e); 190 count++; 191 } 192 break; 193 } 194 } 195 System.out.println("正确率："+(100-(count/number)*100)+"%"); 196 System.out.println("错题数目："+count); 197 System.out.println("错题："+s); 198 } 199 200 public Grade3() { 201 super(); 202 } 203 }
1 import java.util.Scanner; 2 public class Grade4 extends Grade3{ 3 static Scanner sc=new Scanner(System.in); 4 static int[] q=new int[100]; 5 public static void select1() { 6 System.out.println("请选择操作数：1:2个；2:3个；3:4个；4:5个(含括号)"); 7 int i=sc.nextInt(); 8 switch(i) { 9 case 1:answer1(); 10 break; 11 case 2:answer2(); 12 break; 13 case 3:answer3(); 14 break; 15 case 4:answer4(); 16 break; 17 } 18 } 19 20 public static void answer1() { 21 double count=0; 22 System.out.print("请输入范围（<=100）："); 23 num=sc.nextInt(); 24 System.out.print("请输入题目数(>30)："); 25 int number=sc.nextInt(); 26 for(i=0;i<2*number;i++) { 27 m[i]=r.nextInt(num)+1; 28 n[i]=r.nextInt(num)+1; 29 for(int j=0;j<i;j++) { 30 if(m[i]==m[j]&&n[i]==n[j]) { 31 m[i]=r.nextInt(num)+1; 32 } 33 } 34 int k=r.nextInt(4)+1; 35 switch(k) { 36 case 0:System.out.println(m[i]+"+"+n[i]+"="); 37 double a=sc.nextInt(); 38 System.out.println("正确答案："+(m[i]+n[i])); 39 if(a!=(m[i]+n[i])) { 40 String e=m[i]+"+"+n[i]+"="; 41 s.add(e); 42 count++; 43 } 44 break; 45 case 1:System.out.println(m[i]+"-"+n[i]+"="); 46 double b=sc.nextInt(); 47 System.out.println("正确答案："+(m[i]-n[i])); 48 if(b!=(m[i]-n[i])) { 49 String e=m[i]+"-"+n[i]+"="; 50 s.add(e); 51 count++; 52 } 53 break; 54 case 2:System.out.println(m[i]+"*"+n[i]+"="); 55 double c=sc.nextInt(); 56 System.out.println("正确答案："+(m[i]*n[i])); 57 if(c!=(m[i]*n[i])) { 58 String e=m[i]+"*"+n[i]+"="; 59 s.add(e); 60 count++; 61 } 62 break; 63 case 3:System.out.println(m[i]+"/"+n[i]+"="); 64 double d=sc.nextInt(); 65 System.out.println("正确答案："+(m[i]/n[i])); 66 if(d!=(m[i]/n[i])) { 67 String e=m[i]+"/"+n[i]+"="; 68 s.add(e); 69 count++; 70 } 71 break; 72 } 73 } 74 System.out.println("正确率："+(100-(count/number)*100)+"%"); 75 System.out.println("错题数目："+count); 76 System.out.println("错题："+s); 77 } 78 79 80 public static void answer2() { 81 double count=0; 82 System.out.print("请输入范围（<=1000）："); 83 num=sc.nextInt(); 84 System.out.print("请输入题目数(>30)："); 85 int number=sc.nextInt(); 86 for(i=0;i<2*number;i++) { 87 m[i]=r.nextInt(num)+1; 88 n[i]=r.nextInt(num)+1; 89 j[i]=r.nextInt(num)+1; 90 for(int j=0;j<i;j++) { 91 if(m[i]==m[j]&&n[i]==n[j]) { 92 m[i]=r.nextInt(num)+1; 93 } 94 } 95 int k=r.nextInt(4)+1; 96 switch(k) { 97 case 0:System.out.println(m[i]+"+"+n[i]+"-"+j[i]+"="); 98 double a=sc.nextInt(); 99 System.out.println("正确答案："+(m[i]+n[i]-j[i])); 100 if(a!=(m[i]+n[i])) { 101 String e=m[i]+"+"+n[i]+"-"+j[i]+"="; 102 s.add(e); 103 count++; 104 } 105 break; 106 case 1:System.out.println(j[i]+"*"+m[i]+"-"+n[i]+"="); 107 double b=sc.nextInt(); 108 System.out.println("正确答案："+(j[i]*m[i]-n[i])); 109 if(b!=(m[i]-n[i])) { 110 String e=j[i]+"*"+m[i]+"-"+n[i]+"="; 111 s.add(e); 112 count++; 113 } 114 break; 115 case 2:System.out.println(m[i]+"*"+n[i]+"/"+j[i]+"="); 116 double c=sc.nextInt(); 117 System.out.println("正确答案："+(m[i]*n[i]/j[i])); 118 if(c!=(m[i]*n[i])) { 119 String e=m[i]+"*"+n[i]+"/"+j[i]+"="; 120 s.add(e); 121 count++; 122 } 123 break; 124 case 3:System.out.println(m[i]+"/"+n[i]+"+"+j[i]+"="); 125 double d=sc.nextInt(); 126 System.out.println("正确答案："+(m[i]/n[i]+j[i])); 127 if(d!=(m[i]/n[i])) { 128 String e=m[i]+"/"+n[i]+"+"+j[i]+"="; 129 s.add(e); 130 count++; 131 } 132 break; 133 } 134 } 135 System.out.println("正确率："+(100-(count/number)*100)+"%"); 136 System.out.println("错题数目："+count); 137 System.out.println("错题："+s); 138 } 139 140 public static void answer3() { 141 double count=0; 142 System.out.print("请输入范围（<=1000）："); 143 num=sc.nextInt(); 144 System.out.print("请输入题目数(>30)："); 145 int number=sc.nextInt(); 146 for(i=0;i<2*number;i++) { 147 m[i]=r.nextInt(num)+1; 148 n[i]=r.nextInt(num)+1; 149 j[i]=r.nextInt(num)+1; 150 z[i]=r.nextInt(num)+1; 151 for(int j=0;j<i;j++) { 152 if(m[i]==m[j]&&n[i]==n[j]) { 153 m[i]=r.nextInt(num)+1; 154 } 155 } 156 int k=r.nextInt(4)+1; 157 switch(k) { 158 case 0:System.out.println(z[i]+"*"+m[i]+"+"+n[i]+"-"+j[i]+"="); 159 double a=sc.nextInt(); 160 System.out.println("正确答案："+(z[i]*m[i]+n[i]-j[i])); 161 if(a!=(m[i]+n[i])) { 162 String e=z[i]+"*"+m[i]+"+"+n[i]+"-"+j[i]+"="; 163 s.add(e); 164 count++; 165 } 166 break; 167 case 1:System.out.println(m[i]+"/"+j[i]+"+"+z[i]+"-"+n[i]+"="); 168 double b=sc.nextInt(); 169 System.out.println("正确答案："+(m[i]/j[i]+z[i]-n[i])); 170 if(b!=(m[i]-n[i])) { 171 String e=m[i]+"/"+j[i]+"+"+z[i]+"-"+n[i]+"="; 172 s.add(e); 173 count++; 174 } 175 break; 176 case 2:System.out.println(z[i]+"-"+m[i]+"*"+n[i]+"/"+j[i]+"="); 177 double c=sc.nextInt(); 178 System.out.println("正确答案："+(z[i]-m[i]*n[i]/j[i])); 179 if(c!=(m[i]*n[i])) { 180 String e=z[i]+"-"+m[i]+"*"+n[i]+"/"+j[i]+"="; 181 s.add(e); 182 count++; 183 } 184 break; 185 case 3:System.out.println(j[i]+"-"+m[i]+"/"+z[i]+"-"+n[i]+"="); 186 double d=sc.nextInt(); 187 System.out.println("正确答案："+(j[i]-m[i]/z[i]-n[i])); 188 if(d!=(m[i]/n[i])) { 189 String e=j[i]+"-"+m[i]+"/"+z[i]+"-"+n[i]+"="; 190 s.add(e); 191 count++; 192 } 193 break; 194 } 195 } 196 System.out.println("正确率："+(100-(count/number)*100)+"%"); 197 System.out.println("错题数目："+count); 198 System.out.println("错题："+s); 199 } 200 201 public static void answer4() { 202 double count=0; 203 System.out.print("请输入范围（<=1000）："); 204 num=sc.nextInt(); 205 System.out.print("请输入题目数(>30)："); 206 int number=sc.nextInt(); 207 for(i=0;i<2*number;i++) { 208 m[i]=r.nextInt(num)+1; 209 n[i]=r.nextInt(num)+1; 210 j[i]=r.nextInt(num)+1; 211 z[i]=r.nextInt(num)+1; 212 q[i]=r.nextInt(num)+1; 213 for(int j=0;j<i;j++) { 214 if(m[i]==m[j]&&n[i]==n[j]) { 215 m[i]=r.nextInt(num)+1; 216 } 217 } 218 int k=r.nextInt(4)+1; 219 switch(k) { 220 case 0:System.out.println(z[i]+"-"+q[i]+"*"+"("+m[i]+"+"+n[i]+")"+"-"+j[i]+"="); 221 double a=sc.nextInt(); 222 System.out.println("正确答案："+(z[i]-q[i]*(m[i]+n[i])-j[i])); 223 if(a!=(m[i]+n[i])) { 224 String e=z[i]+"-"+q[i]+"*"+"("+m[i]+"+"+n[i]+")"+"-"+j[i]+"="; 225 s.add(e); 226 count++; 227 } 228 break; 229 case 1:System.out.println(m[i]+"-"+q[i]+"/"+j[i]+"+"+z[i]+"-"+n[i]+"="); 230 double b=sc.nextInt(); 231 System.out.println("正确答案："+(m[i]-q[i]/j[i]+z[i]-n[i])); 232 if(b!=(m[i]-n[i])) { 233 String e=m[i]+"-"+q[i]+"/"+j[i]+"+"+z[i]+"-"+n[i]+"="; 234 s.add(e); 235 count++; 236 } 237 break; 238 case 2:System.out.println((z[i]+"-"+m[i]+"*"+q[i])+"*"+n[i]+"/"+j[i]+"="); 239 double c=sc.nextInt(); 240 System.out.println("正确答案："+((z[i]-m[i]*q[i])*n[i]/j[i])); 241 if(c!=(m[i]*n[i])) { 242 String e=(z[i]+"-"+m[i]+"*"+q[i])+"*"+n[i]+"/"+j[i]+"="; 243 s.add(e); 244 count++; 245 } 246 break; 247 case 3:System.out.println(j[i]+"-"+m[i]+"/"+(z[i]+"-"+n[i])+"/"+q[i]+"="); 248 double d=sc.nextInt(); 249 System.out.println("正确答案："+(j[i]-m[i]/(z[i]-n[i])/q[i])); 250 if(d!=(m[i]/n[i])) { 251 String e=j[i]+"-"+m[i]+"/"+(z[i]+"-"+n[i])+"/"+q[i]+"="; 252 s.add(e); 253 count++; 254 } 255 break; 256 } 257 } 258 System.out.println("正确率："+(100-(count/number)*100)+"%"); 259 System.out.println("错题数目："+count); 260 System.out.println("错题："+s); 261 } 262 263 }
Grade3和Grade4要求操作较多，代码较长。
