Code Kata:大整数四则运算—除?法 javascript实现

 1 function division(a, b) { /*输入两个字符串类型大数字*/
 2 
 3     a = a.toString();
 4 
 5     b = b.toString();
 6 
 7     var sign = ‘‘;
 8 
 9     if(a.indexOf(‘-‘) >= 0 && b.indexOf(‘-‘) < 0){
10 
11         sign = ‘-‘;
12 
13         a = a.substr(1);
14     }
15     else if(a.indexOf(‘-‘) < 0 && b.indexOf(‘-‘) >= 0){
16 
17         sign = ‘-‘;
18 
19         b = b.substr(1);
20     }
21 
22     if(a.indexOf(‘-‘) >= 0 && b.indexOf(‘-‘) >= 0){
23 
24         a = a.substr(1);
25 
26         b = b.substr(1);
27     }
28 
29     if(compare(a,b) < 0){   /*绝对值a<b返回0*/
30 
31         return 0;
32     }
33 
34     a = a.replace(/^0+/,‘‘);
35 
36     b = b.replace(/^0+/,‘‘);
37 
38     var divisionSub = function(x,y){
39 
40         var returnRes = [0];
41 
42         var xlen = x.length;
43 
44         var ylen = y.length;
45 
46         for(var i=0;i<xlen-ylen;i++){
47 
48             if(compare(x,y + ‘0‘) >= 0){
49 
50                 y += "0";
51 
52                 returnRes.push(0);
53             }
54         }
55 
56         while(compare(x,y) >= 0){
57 
58             returnRes[0] ++;
59 
60             x = subtraction(x,y);
61         }
62 
63         return {
64             remainder : x,
65             quotient : returnRes.join(‘‘)
66         }
67     }
68 
69     var divisionRes = ‘0‘;
70 
71     var divisionSubRes = {
72         remainder: a,
73         quotient: ‘0‘
74     }
75 
76     while(compare(divisionSubRes.remainder,b) >= 0){
77 
78         divisionSubRes = divisionSub(divisionSubRes.remainder,b);
79 
80         divisionRes = addition(divisionRes,divisionSubRes.quotient);
81 
82     }
83 
84     return sign + divisionRes;
85 }