Problem Description
I have a very simple problem for you. Given two integers A and B, your job is to calculate the Sum of A + B.
 
Input
The first line of the input contains an integer T(1<=T<=20) which means the number of test cases. Then T lines follow, each line consists of two positive integers, A and B. Notice that the integers are very large, that means you should not process them by using 32-bit integer. You may assume the length of each integer will not exceed 1000.
 
Output
For each test case, you should output two lines. The first line is "Case #:", # means the number of the test case. The second line is the an equation "A + B = Sum", Sum means the result of A + B. Note there are some spaces int the equation. Output a blank line between two test cases.
 
Sample Input
2 1 2 112233445566778899 998877665544332211
 
Sample Output
Case 1: 1 + 2 = 3 Case 2: 112233445566778899 + 998877665544332211 = 1111111111111111110
 
C++代码:
编写了一个长整数类，重载'+'运算符
  1 #include<iostream>
  2 #include<string>
  3 using namespace std;
  4 class LongInt
  5 {
  6 public:
  7     LongInt()   //默认构造函数
  8     {
  9         size=0;
 10     }
 11     LongInt(string &t)
 12     {
 13         a=t;
 14         size=t.size();
 15     }
 16     LongInt(const LongInt &t)
 17     {
 18         a=t.a;
 19         size=t.size;
 20     }
 21     void Get(string &t)    //输入
 22     {
 23         a=t;
 24         size=t.size();
 25     }
 26     string operator+(const LongInt &t)
 27     {//把长度长的放到字符串temp里，再把另一个加到temp里，最后遍历temp，该进位的进位，该降位的降位
 28         if(size>t.size)
 29         {
 30             string temp(size,'\0');
 31             for(int i=0;i<size-t.size;i++)
 32                 temp[i]=a[i];
 33             for(int i=size-t.size;i<size;i++)
 34                 temp[i]=a[i]+t.a[i-size+t.size]-'0';
 35             for(int i=size-1;i>0;i--)
 36                 if(temp[i]>'9')
 37                 {
 38                     temp[i-1]++;
 39                     temp[i]-=10;
 40                 }
 41             if(temp[0]>'9')
 42             {
 43                 string _temp(temp+"a");
 44                 for(int i=size;i>0;i--)
 45                     _temp[i]=_temp[i-1];
 46                 _temp[1]-=10;
 47                 _temp[0]='1';
 48                 return _temp;
 49             }
 50             return temp;
 51         }
 52         else if(size<t.size)
 53         {
 54             string temp(t.size,'\0');
 55             for(int i=0;i<t.size-size;i++)
 56                 temp[i]=t.a[i];
 57             for(int i=t.size-size;i<t.size;i++)
 58                 temp[i]=t.a[i]+a[i-t.size+size]-'0';
 59             for(int i=t.size-1;i>0;i--)
 60                 if(temp[i]>'9')
 61                 {
 62                     temp[i-1]++;
 63                     temp[i]-=10;
 64                 }
 65             if(temp[0]>'9')
 66             {
 67                 string _temp(temp+"a");
 68                 for(int i=size;i>0;i--)
 69                     _temp[i]=_temp[i-1];
 70                 _temp[1]-=10;
 71                 _temp[0]='1';
 72                 return _temp;
 73             }
 74             return temp;
 75         }
 76         else if(size==t.size)
 77         {
 78             string temp(size,'\0');
 79             for(int i=0;i<size;i++)
 80                 temp[i]=a[i]+t.a[i]-'0';
 81             for(int i=size-1;i>0;i--)
 82                 if(temp[i]>'9')
 83                 {
 84                     temp[i-1]++;
 85                     temp[i]-=10;
 86                 }
 87             if(temp[0]>'9')
 88             {
 89                 string _temp(temp+"a");
 90                 for(int i=size;i>0;i--)
 91                     _temp[i]=_temp[i-1];
 92                 _temp[1]-=10;
 93                 _temp[0]='1';
 94                 return _temp;
 95             }
 96             return temp;
 97         }
 98     }
 99 private:
100     string a;
101     int size;
102 };
103 int main()
104 {
105     LongInt a,b;
106     string _a,_b;
107     int n;
108     cin>>n;
109     for(int i=1;i<=n;i++)
110     {
111         cin>>_a>>_b;
112         a.Get(_a);
113         b.Get(_b);
114         cout<<"Case "<<i<<':'<<endl<<_a<<' '<<'+'<<' '<<_b<<' '<<'='<<' '<<a+b<<endl;
115         if(i!=n)
116             cout<<endl;
117     }
118 }
View Code