my高精模板

网上的鱼龙混杂，不如自己写个。

 1 char str[1000];
 2 int a[1000],b[1000],c[1000];
 3 
 4 int main(){
 5     scanf("%s",str);
 6     int len = strlen(str);
 7     for(int i = len-1;i >= 0;i--)a[len-i] = str[i]-'0';
 8     scanf("%s",str);
 9     int n = len;
10     len = strlen(str);
11     for(int i = len-1;i >= 0;i--)b[len-i] = str[i]-'0';
12     int m = len;
13     n = max(n,m); 
14     
15     for(int i = 1;i <= n;i++)c[i] = a[i]+b[i];
16     for(int i = 1;i <= n;i++)c[i+1] += c[i]/10,c[i] %= 10;
17     while(c[n] > 10||c[n+1])c[n+1] += c[n]/10,c[n] %= 10,n++;
18     
19     for(int i = n;i > 0;i--)putchar(c[i]+'0');putchar('
');
20     
21 return 0;
22 }

 1 char s[1000];
 2 int b;
 3 int a[1000],c[1000];
 4 int n,m;
 5 
 6 int main(){
 7     scanf("%s",s);
 8     int n = strlen(s);
 9     for(int i = n-1;i >= 0;i--)a[n-i] = s[i] - '0';
10     scanf("%d",&b);
11     
12     for(int i = 1;i <= n;i++)c[i] = a[i]*b;
13     for(int i = 1;i <= n;i++)c[i+1] += c[i]/10,c[i] %= 10;
14     while(c[n] > 10||c[n+1])c[n+1] += c[n]/10,c[n] %= 10,n++;
15     
16     for(int i = n;i >= 1;i--)putchar(c[i]+'0');
17     
18 return 0;
19 }

 1 #include<iostream>
 2 #include<cstdio> 
 3 #include<cstring>
 4 #include<cmath>
 5 #include<cstdlib>
 6 #include<algorithm>
 7 using namespace std;
 8 
 9 struct bignum{
10     int a[1000];
11     int len;
12     
13     void init(){memset(a,0,sizeof(a));}
14     
15     void get(){
16         init();
17         char s[1000];
18         scanf("%s",s);
19         len = strlen(s);
20         for(int i = len-1;i >= 0;i--)a[len-i] = s[i]-'0';
21     }
22     
23     void print(){
24         for(int i = len;i > 0;i--)putchar(a[i]+'0');
25     }
26     
27     void initlen(){
28         for(len = 999;len > 0;len--)if(a[len])break;
29     }
30     
31     bignum operator *(const bignum& x){
32         bignum ans;
33         ans.init();
34         for(int i = 1;i <= len;i++)
35             for(int j = 1;j <= x.len;j++)
36                 ans.a[i+j-1] += a[i]*x.a[j];
37         for(int i = 1;i < 1000;i++)ans.a[i+1] += ans.a[i]/10,ans.a[i] %= 10;
38         ans.initlen();
39         return ans;
40     }
41     
42 }x,y,z;
43 
44 bignum div(bignum x,int y){
45     bignum ans;
46     ans.init();
47     int now = 0,cur = x.len+1;
48     while(now < y){
49         cur--;
50         now = now*10+x.a[cur];
51     }
52     ans.len = cur;
53     while(cur){
54         ans.a[cur] = now/y; cur--;
55         now = now%y*10+x.a[cur];
56     }
57     return ans;
58 }
59 
60 int w;
61 
62 int main(){
63     x.get(); cin >> w;
64     div(x,w).print();
65 return 0;
66 }

final