练习11 | 易学教程

 1 //-------------------------------------
 2 // EX1101.cpp
 3 // 解方程
 4 //-------------------------------------
 5 #include"Root.h"
 6 #include<iostream>
 7 using namespace std;
 8 //-------------------------------------
 9 int main(){
10   for(double a,b,c; cin>>a>>b>>c; )
11     Root(a,b,c).solve();
12 }//------------------------------------

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 1 //-------------------------------------
 2 // Root.h
 3 //-------------------------------------
 4 #ifndef HEADER_ROOT
 5 #define HEADER_ROOT
 6 //-------------------------------------
 7 class Root{
 8   double aa,bb,cc;
 9 public:
10   Root(double a, double b, double c):aa(a), bb(b), cc(c){}
11   void solve()const;
12 };//-----------------------------------
13 #endif   // HEADER_ROOT
14 
15 /*
16 #ifndef HEADER_ROOT
17 #define HEARDER_ROOT
18 
19 
20 #endif HEADER_ROOT
21 */

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 1 //-------------------------------------
 2 // Root.cpp
 3 //-------------------------------------
 4 #include"Root.h"
 5 #include"Complex.h"
 6 #include<cmath>  // for sqrt()
 7 //-------------------------------------
 8 void Root::solve()const{
 9   Complex x1(-bb/(2*aa)), x2(-bb/(2*aa));
10   double delta = bb*bb - 4*aa*cc;
11   if(delta){
12     bool flag=delta<0;
13     delta = (flag?-1:1)*delta;//三目运算符,-1乘以负的delta得正数
14     delta = std::sqrt(delta)/(2*aa);
15     if(flag)
16         x1.im = delta, x2.im = -delta;//imag
17     else   
18         x1.re += delta, x2.re -= delta;//real
19   }
20   cout<<"The solution is\n";
21   cout<<"  x1 = "<<x1<<"\n";
22   cout<<"  x2 = "<<x2<<"\n";
23 }//------------------------------------

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 1 //-------------------------------------
 2 // Real.h
 3 //-------------------------------------
 4 #ifndef HEADER_REAL
 5 #define HEADER_REAL
 6 #include<iostream>
 7 using namespace std;
 8 //-------------------------------------
 9 class Real{
10 protected:
11   double real;
12 public:
13   Real(double r=0):real(r){}
14    double(const Real& a){ return a.real; }
15   friend Real operator+(const Real& a, const Real& b){ return a.real+b.real; }
16   friend Real operator-(const Real& a, const Real& b){ return a.real-b.real; }
17   friend Real operator*(const Real& a, const Real& b){ return a.real*b.real; }
18   friend Real operator/(const Real& a, const Real& b){ return a.real/b.real; }
19   friend bool operator==(const Real& a, const Real& b){ return a.real==b.real; }
20   friend ostream& operator<<(ostream& cout, const Real& a){ return cout<<a.real; }
21   //friend class Root;
22 };//-----------------------------------
23 #endif   // HEADER_REAL
24      
25 
26

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 1 //-------------------------------------
 2 // Real.cpp
 3 //-------------------------------------
 4 #ifndef HEADER_COMPLEX
 5 #define HEADER_COMPLEX
 6 #include<iostream>
 7 using namespace std;
 8 //-------------------------------------
 9 class Complex{
10   double real, virt;
11 public:
12   Complex(double r=0, double v=0):real(r),virt(v){}
13   friend Complex operator+(const Complex& a, const Complex& b);
14   friend ostream& operator<<(ostream& out, const Complex& a);
15 };//-----------------------------------
16 #endif   // HEADER_COMPLEX
17      
18 
19

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 1 //-------------------------------------
 2 // Complex.h
 3 //-------------------------------------
 4 #ifndef HEADER_COMPLEX
 5 #define HEADER_COMPLEX
 6 #include<iostream>
 7 using namespace std;
 8 //-------------------------------------
 9 class Complex{
10 protected:
11   double re, im;
12 public:
13   Complex(double r=0, double v=0):re(r),im(v){}
14   friend Complex operator+(const Complex& a, const Complex& b);
15   friend ostream& operator<<(ostream& out, const Complex& a);
16   friend class Root;
17 };//-----------------------------------
18 #endif   // HEADER_COMPLEX
19

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 1 //-------------------------------------
 2 // Complex.cpp
 3 //-------------------------------------
 4 #include"Complex.h"
 5 #include<iostream>
 6 using namespace std;
 7 //-------------------------------------
 8 ostream& operator<<(ostream& cout, const Complex& a){
 9   return (a.im ? cout<<a.re<<" + "<<a.im<<"i" : cout<<a.re);
10 }//------------------------------------
11 Complex operator+(const Complex& a, const Complex& b){
12   return Complex(a.re+b.re, a.im+b.im);
13 }//--------------------------

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 1 //=====================================
 2 // EX1102_2.cpp
 3 // 大数A+B (对象版)
 4 //=====================================
 5 #include"Number.h"
 6 #include<fstream>
 7 #include<iostream>
 8 using namespace std;
 9 //-------------------------------------
10 int main(){
11   ifstream cin("aplusb.in");
12   for(Number a,b; cin>>a>>b; )
13     cout<<a+b<<"\n";
14 }//====================================
15

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 1 //=====================================
 2 // Number.cpp
 3 //=====================================
 4 #include"Number.h"
 5 #include<iostream>
 6 #include<string>
 7 #include<vector>
 8 using namespace std;
 9 //-------------------------------------
10 void Number::add(const Number& a){
11   for(int i=s.length()-1,tmp=0; i>=0; --i, tmp/=10){
12     tmp += a.s[i]-'0'+ s[i]-'0';
13     s[i] = tmp%10 + '0';
14   }
15 }//------------------------------------
16 void Number::comple(string& t){                 // 十进数取补
17   for(int i=0; i<t.length(); ++i) //取反
18     t[i] = 105 - t[i];  // '0'+'9'=105
19   int i=t.length()-1;
20   while(i>=0 && t[i]=='9')        //+1
21     t[i--]='0';
22   t[i]++;
23 }//------------------------------------
24 void Number::stretch(){               // 伸展至Num位
25   if(s[0]!='-')
26     s = string(Num-s.length(),'0')+s;
27   else{
28     s[0]='0';
29     comple(s);
30     s = string(Num-s.length(),'9')+s;
31   }
32 }//------------------------------------
33 string Number::shrink()const{                // 按有效位压缩
34   string t(s);
35   if(t[0]=='9')
36     comple(t);
37   int pos = t.find_first_not_of('0');
38   if(pos<0) return string("0");
39   return (s[0]=='9'? "-":"")+t.substr(pos);
40 }//------------------------------------
41 Number operator+(const Number& a, const Number& b){
42   Number w(a);
43   w.add(b);  // w+=t
44   return w;
45 }//------------------------------------
46 istream& operator>>(istream& cin, Number& a){
47   cin>>a.s;
48   a.stretch();
49   return cin;
50 }//------------------------------------
51 ostream& operator<<(ostream& cout, const Number& a){
52   return cout<<a.shrink();
53 }//------------------------------------

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 1 //=====================================
 2 // Number.h
 3 // 大数类
 4 //=====================================
 5 #ifndef HEADER_NUMBER
 6 #define HEADER_NUMBER
 7 #include<iostream>
 8 #include<string>
 9 using namespace std;
10 //-------------------------------------
11 class Number{
12   string s;
13   void comple(string& s);     //s取补
14   void stretch();             //s伸展,用于初始化
15   string shrink()const;       //s压缩
16   enum { Num=80 };
17 public:
18   Number():s(Num,'0'){}
19   Number(const string& a):s(a){ stretch(); }
20   void add(const Number& a);  //s+=a
21   friend Number operator+(const Number& a, const Number& b);
22   friend istream& operator>>(istream& cin, Number& a);
23   friend ostream& operator<<(ostream& cout, const Number& a);
24 };//-----------------------------------
25 #endif  // HEADER_NUMBER

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字串是从零开始的 下标0表示第一个字符length 返回的实际内容的长度 不包括０3

 1 //=====================================
 2 // Number.cpp
 3 //=====================================
 4 #include"Number.h"
 5 #include<iostream>
 6 #include<string>
 7 using namespace std;
 8 //-------------------------------------
 9 static void sub(string& x, const string& k);
10 //-------------------------------------
11 string Number::div(int n)const{
12   string p(s), res=(p[0]=='9'?"-":"");
13   if(p[0]=='9') comple(p);
14   int pos=p.find_first_not_of('0');
15   if(pos<0) return string();
16   p=p.substr(pos);
17 
18   string k;
19   for( ; n; n/=10) k = char(n%10+'0')+k;
20 
21   if(k.length()>p.length()) return string();
22 
23   int m = k.length()-(p.substr(0,k.length())>=k);
24   string x(p.substr(0, m));
25   for(int i=m; i<p.length(); ++i){
26     x += p[i];
27     int count=0;
28     for( ; x.length()>=k.length() && x>=k; count++)
29       sub(x,k);
30     res += char(count+'0');
31   }
32   return res;  // x abandoned
33 }//------------------------------------
34 void sub(string& x, const string& k){
35   int tmp=0,h=x.length()-k.length();
36   for(int i=k.length()-1; i>=0; --i){
37     tmp=x[i+h]-k[i]-tmp;
38     if(tmp>=0) x[i+h]=tmp+'0', tmp=0;
39     else x[i+h]=10+tmp+'0', tmp=1;
40   }
41   if(tmp) x[0]--;
42   int pos = x.find_first_not_of('0');
43   x = (pos<0 ? string() : x.substr(pos));
44 }//------------------------------------
45 void Number::operator()(const Number& a){
46   add(a);
47   cout<<a.shrink()<<"\n";
48 }//------------------------------------
49 bool operator<(const Number& a, const Number& b){
50   if(a.s[0]=='9' && b.s[0]!='9') return true;
51   if(a.s[0]!='9' && b.s[0]=='9') return false;
52   return a.s<b.s;
53 }//------------------------------------
54 void Number::add(const Number& a){
55   for(int i=s.length()-1,tmp=0; i>=0; --i, tmp/=10){
56     tmp += a.s[i]-'0'+ s[i]-'0';
57     s[i] = tmp%10 + '0';
58   }
59 }//------------------------------------
60 void Number::comple(string& t){                 // 十进数取补
61   for(int i=0; i<t.length(); ++i) //取反
62     t[i] = 105 - t[i];  // '0'+'9'=105
63   int i=t.length()-1;
64   while(i>=0 && t[i]=='9')        //+1
65     t[i--]='0';
66   t[i]++;
67 }//------------------------------------
68 void Number::stretch(){               // 伸展至Num位
69   if(s[0]!='-')
70     s = string(Num-s.length(),'0')+s;
71   else{
72     s[0]='0';
73     comple(s);
74     s = string(Num-s.length(),'9')+s;
75   }
76 }//------------------------------------
77 string Number::shrink()const{                // 按有效位压缩
78   string t(s);
79   if(t[0]=='9')
80     comple(t);
81   int pos = t.find_first_not_of('0');
82   if(pos<0) return string("0");
83   return (s[0]=='9'? "-":"")+t.substr(pos);
84 }//------------------------------------
85 Number operator+(const Number& a, const Number& b){
86   Number w(a);
87   w.add(b);  // s+=t
88   return w;
89 }//------------------------------------
90 istream& operator>>(istream& cin, Number& a){
91   cin>>a.s;
92   a.stretch();
93   return cin;
94 }//------------------------------------
95 ostream& operator<<(ostream& cout, const Number& a){
96   return cout<<a.shrink();
97 }//------------------------------------

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 1 //=====================================
 2 // Number.h
 3 // 大数类
 4 //=====================================
 5 #ifndef HEADER_NUMBER
 6 #define HEADER_NUMBER
 7 #include<iostream>
 8 #include<string>
 9 using namespace std;
10 //-------------------------------------
11 class Number{
12   string s;
13   void comple(string& s);     //s取补
14   void stretch();             //s伸展,用于初始化
15   string shrink()const;       //s压缩
16   enum { Num=100 };
17 public:
18   Number():s(string(Num,'0')){}
19   Number(const string& a):s(a){ stretch(); }
20   string div(int n)const;
21   void add(const Number& a);  //s+=a
22   void operator()(const Number& a);
23   friend bool operator<(const Number& a, const Number& b);
24   friend Number operator+(const Number& a, const Number& b);
25   friend istream& operator>>(istream& cin, Number& a);
26   friend ostream& operator<<(ostream& cout, const Number& a);
27 };//-----------------------------------
28 #endif  // HEADER_NUMBER

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 1 //=====================================
 2 // EX1102_2.cpp
 3 // 大数排序+求平均数
 4 //=====================================
 5 #include"Number.h"
 6 #include<fstream>
 7 #include<iostream>
 8 #include<vector>
 9 #include<algorithm>  // sort, for_each
10 using namespace std;
11 //-------------------------------------
12 int main(){
13   ifstream cin("aplusb.in");
14   vector<Number> x;
15   for(Number a; cin>>a; )
16     x.push_back(a);
17   sort(x.begin(), x.end());
18   Number sum = for_each(x.begin(), x.end(), Number());
19   cout<<"Average: "<<sum.div(x.size())<<"\n";
20 }//====================================

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 1 //=====================================
 2 // EX1102_1.cpp
 3 // 大数排序+求平均数
 4 //=====================================
 5 #include"Number.h"
 6 #include<fstream>
 7 #include<iostream>
 8 #include<vector>
 9 #include<algorithm>  // sort
10 using namespace std;
11 //-------------------------------------
12 int main(){
13   ifstream cin("aplusb.in");
14   vector<Number> x;
15   for(Number a; cin>>a; )
16     x.push_back(a);
17   sort(x.begin(), x.end());
18   Number sum;
19   for(int i=0; i<x.size(); i++){
20     sum.add(x[i]);
21     cout<<x[i]<<"\n";
22   }
23   cout<<"Average: "<<sum.div(x.size())<<"\n";
24 }//====================================

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来源：https://www.cnblogs.com/herizai/p/3145036.html

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