1 package com.calutate;
2
3 import java.util.*;
4
5 public class Precision
6 {
7 int max=100000;
8
9
10 public void Calculate()
11 {
12 int base=0;
13 int len=0;
14 int doclen=0;//真实小数位数
15 int integerlen=0;//整数位数
16 int totaldoclen=0;//计算结果小数位数
17 int totallen=0;//计算结果总位数
18 int ns=0;//n次幂
19 int set=0;
20
21 String inputs=new String();
22 Scanner cin;
23 Scanner cinn;
24
25 do
26 {
27 base=0;
28 int[] result=new int[max];
29 System.out.println("输入数据:");
30 cin=new Scanner(System.in);
31 inputs=cin.nextLine();
32 System.out.println("输入n：");
33 cinn=new Scanner(System.in);
34 ns=cinn.nextInt();
35
36 char[] cs=inputs.toCharArray();
37 len=this.realLength(cs);
38 for (int i = 0; i < len; i++)
39 {
40
41 if(cs[i]!='.')
42 {
43 int sxs=Integer.parseInt(String.valueOf(cs[i]));
44 base=base*10+sxs;
45 }else
46 {
47 integerlen=this.Intlength(base);
48 }
49
50 }
51 totallen=this.Intlength(base);
52 doclen=totallen-integerlen;
53
54
55 totaldoclen=doclen*ns;
56 int based=base;
57 for (int i = 0; i < len; i++)
58 {
59 result[i]=based%10;
60 based=based/10;
61 }
62 for (int i = 0; i < ns-1; i++)
63 {
64 for (int j = 0; j <max; j++)
65 {
66 result[j]=result[j]*base+set;
67 set=result[j]/10;
68 result[j]=result[j]%10;
69 }
70 }
71
72 totallen=this.realLength(result);
73 if (integerlen>0)
74 {
75 for (int i = totallen-1; i >=totaldoclen; i--)
76 {
77 System.out.print(result[i]);
78 }
79 if(totaldoclen>0)
80 {
81 System.out.print(".");
82 for (int i = totaldoclen-1; i >=0; i--)
83 {
84 System.out.print(result[i]);
85 }
86 }
87 }
88 else
89 {
90 System.out.print(".");
91 for (int i = totaldoclen-1; i >=0; i--)
92 {
93 System.out.print(result[i]);
94 }
95 }
96 System.out.println();
97 // cin.close();
98 // cinn.close();
99 }while(inputs!="0");
100
101 cin.close();
102 cinn.close();
103 }
104
105 /*
106 计算有效数值长度
107 * */
108 private int realLength(int[] a)
109 {
110 int relLength=0;
111 for (int i = a.length-1; i >= 0; i--)
112 {
113 if(a[i]!=0)
114 {
115 relLength=i+1;
116 break;
117 }
118 }
119 return relLength;
120
121 }
122
123 private int realLength(char[] a)
124 {
125 int relLength=0;
126 for (int i = a.length-1; i >= 0; i--)
127 {
128 if(a[i]!='0')
129 {
130 relLength=i+1;
131 break;
132 }
133 }
134 return relLength;
135
136 }
137
138 /*
139 计算整数长度
140 */
141 private int Intlength(int a)
142 {
143 int leng=0;
144 while (a>0)
145 {
146 a=a/10;
147 leng++;
148 }
149 return leng;
150
151 }
152 }
