UVA 424-Integer Inquiry

Posted 2020-07-03

题意：连续大数加法，

分析：用c++大整数模板做

 1 #include"iostream"
 2 #include"cstdio"
 3 #include"vector"
 4 #include"algorithm"
 5 #include"cstring"
 6 #include"string"
 7 using namespace std;
 8 
 9 struct BigInteger{
10     static const int BASE=1e8;
11     static const int WIDTH=8;
12     vector<int> s;
13 
14     BigInteger(long long num=0){*this=num;}
15     BigInteger operator = (long long num){
16         s.clear();
17         do{
18             s.push_back(num%BASE);
19             num/=BASE;
20         }while(num>0);
21         return *this;
22     }
23     BigInteger operator =(const string &str){
24         s.clear();
25         int x,len=(str.length()-1)/WIDTH+1;
26         for(int i=0;i<len;i++){
27             int end=str.length()-i*WIDTH;
28             int start=max(0,end-WIDTH);
29             sscanf(str.substr(start,end-start).c_str(),"%d",&x);
30             s.push_back(x);
31         }
32         return *this;
33     }
34     BigInteger operator + (const BigInteger& b)const{
35         BigInteger c;
36         c.s.clear();
37         for(int i=0,g=0;;i++){
38             if(g==0&&i>=s.size()&&i>=b.s.size()) break;
39             int x=g;
40             if(i<s.size()) x+=s[i];
41             if(i<b.s.size()) x+=b.s[i];
42             c.s.push_back(x%BASE);
43             g=x/BASE;
44         }
45         return c;
46     }
47     bool operator < (const BigInteger& b)const{
48         if(s.size()!=b.s.size()) return s.size()<b.s.size();
49         for(int i=s.size()-1;i>=0;i--){
50             if(s[i]!=b.s[i]) return s[i]>b.s[i];
51         }
52         return false;
53     }
54     bool operator !=(const BigInteger& b) const{
55         return b<*this||*this<b;
56     }
57 };
58 ostream& operator << (ostream &out,const BigInteger& x){
59         out<<x.s.back();
60         for(int i=x.s.size()-2;i>=0;i--){
61             char buf[20];
62             sprintf(buf,"%08d",x.s[i]);
63             for(int j=0;j<strlen(buf);j++) out<<buf[j];
64         }
65         return out;
66     }
67     istream& operator >>(istream &in,BigInteger& x){
68         string s;
69         if(!(in>>s)) return in;
70         x=s;
71         return in;
72     }
73 int main()
74 {
75     BigInteger sum=0,x;
76     while(cin>>x&&x!=0)
77     {
78         sum=sum+x;
79     }
80     cout<<sum<<endl;
81     return 0;
82 }