1 #include "../../st.h" 2  3 class Point{ 4 public: 5     Point():x(0),y(0){} 6     Point(int x1,int y1):x(x1),y(y1){} 7     double re_x(){return x;} 8     double re_y(){return y;} 9     friend istream& operator>>(istream&is,Point&p);10 private:11     double x; 12     double y;13 };14 15 ostream& operator<<(ostream& os,Point&p)16 {17     return os<<"("<<p.re_x()<<","<<p.re_y()<<")";18 }19 20 21 istream& operator>>(istream&is,Point&p)22 {23     char c1,c2,c3;24     is>>c1>>p.x>>c2>>p.y>>c3;25     return is;26 }27 28 29 void fill_from_file(vector<Point>&p,string&s)30 {31     ifstream ist(s.c_str());32     if(!ist)33         error("can‘t open input file",s);34     Point pp;35     while(ist>>pp)36         p.push_back(pp);37 }38 39 void file_from_fill(vector<Point>&p,string&s)40 {41     ofstream ost(s.c_str());42     int i;43     if(!ost)44         error("can‘t open output file",s);45     for(i=0;i<p.size();i++)46         ost<<‘(‘<<p[i].re_x()<<‘,‘<<p[i].re_y()<<‘)‘<<endl;47 }48 49 int main()50 {51     int i;52     int x,y;53     vector<Point> original_points;54     vector<Point> processed_points;55     string oname="output.txt";56     57     for(i=0;i<7;i++)58     {59         cout<<i+1<<"  输入（x，y）:";60         cin>>x>>y;61         Point p(x,y);62         original_points.push_back(p);63     }64     65     file_from_fill(original_points,oname);66     fill_from_file(processed_points,oname);67     68     69     for(i=0;i<7;i++)70         cout<<original_points[i]<<endl;71     for(i=0;i<7;i++)72         cout<<processed_points[i]<<endl;73     keep_window_open();74         75 }

 1 #include "../../st.h" 2  3 int main() 4 { 5     string s="mydata.txt"; 6     int i; 7     int sum=0; 8     ifstream ist(s.c_str()); 9     if(!ist)10         error("can‘t open input file",s);11     while(ist>>i)12     {13         sum+=i;14     }15     cout<<sum<<endl;16     keep_window_open();17         18 }         

 1 #include "../../st.h" 2  3 struct Reading{ 4     int hour; 5     double temperature; 6     char c; 7     Reading(int h,double t,char ch):hour(h),temperature(t),c(ch){} 8 }; 9 10 ostream& operator<<(ostream&os,Reading&r)11 {12     return os<<r.hour<<‘,‘<<r.temperature<<r.c<<endl;13 }14 15 istream& operator>>(istream&is,Reading&r)16 {17     char c;18     is>>r.hour>>c>>r.temperature>>r.c;19     return is;20 }21 22 void change(Reading&r)23 {24     if(r.c==‘c‘)25     {26         r.c=‘f‘;27         r.temperature=32+r.temperature*1.8;28     }29 30 }31 32 void fill_from_file(vector<Reading>&r,string&s)33 {34     ifstream ist(s.c_str());35     if(!ist)36         error("can‘t open input file",s);37     Reading rr(0,0,‘c‘);38     while(ist>>rr)39     {40         change(rr);41         r.push_back(rr);42     }43 }44 45 46 int main()47 {48     string s="mydata.txt";49     int hour;50     double tem;51     char ch;52     vector<Reading> readings;53     ofstream ost(s.c_str());54     if(!ost)55         error("can‘t open output file",s);56     while(cin>>hour>>tem>>ch)57     {58         if(hour<0||hour>23)59             error("hour out if range");60         ost<<Reading(hour,tem,ch);61     }62     ost.close();63 64     fill_from_file(readings,s);65     int i,j;66     int h,t;67     for(i=0;i<readings.size();i++)68         for(j=0;j<readings.size()-i-1;j++)69             if(readings[j].temperature>readings[j+1].temperature)70             {71                 h=readings[j].hour;72                 t=readings[j].temperature;73                 readings[j].hour=readings[j+1].hour;74                 readings[j].temperature=readings[j+1].temperature;75                 readings[j+1].hour=h;76                 readings[j+1].temperature=t;77             }78     double sum=0;79     for(i=0;i<readings.size();i++)80         sum+=readings[i].temperature;81     cout<<"middle:"<<readings[readings.size()/2].temperature<<endl<<"平均:"<<sum/readings.size()<<endl;82 83     keep_window_open();84         85 }        

 1 void print_year(ofstream&ofs,Year&y) 2 { 3     ofs<<y.year<<"   year:\n"; 4     for(int i=0;i<12;i++) 5     { 6         if(y.month[i].month!=not_a_month) 7         { 8             ofs<<"\tmonth  "<<y.month[i].month<<endl; 9             for(int j=0;j<32;j++)10             {11                 if(y.month[i].day[i].is_day!=not_a_day)12                 {13                     ofs<<"\t\tday  "<<y.month[i].day[i].is_day<<endl;14                     for(int k=0;k<24;k++)15                         if(y.month[i].day[i].hour[k]!=not_a_reading)16                             ofs<<"\t\t\t"<<i<<" hour: "<<y.month[i].day[i].hour[k]<<endl;17                 }18 19             }20         }21     }22 }    

  1 #include "../../st.h"  2   3 class Roman_int{  4 public:  5     int as_int(string s);  6     int re_int(){return i;}  7     char re_kind(){return ch;}  8     Roman_int()  9         :i(0){} 10     Roman_int(char c) 11         :ch(c),i(0){} 12     Roman_int(char c,int ii) 13         :ch(c),i(ii){} 14 private: 15     int i; 16     char ch; 17 }; 18  19 string as_roman(int i) 20 { 21     if(i<1||i>>3999) 22         error("over range 1~3999"); 23     string digits[10] = {"", "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX"}; 24     string tens[10] = {"", "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC"}; 25     string hundreds[10] = {"", "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM"}; 26     string thousands[4] = {"", "M", "MM", "MMM"}; 27  28     string ss=""; 29     ss+=thousands[i/1000]; 30     ss+=hundreds[i%1000/100]; 31     ss+=tens[i%100/10]; 32     ss+=digits[i%10]; 33  34     return ss; 35 } 36  37 int Roman_int::as_int(string s) 38 { 39     int b[100]; 40     int sum=0; 41     int i1=0,sum1=0; 42     for(i1=0;i1<s.size();i1++) 43     { 44         switch(s[i1]) 45         {  46             case ‘I‘:b[i1]=1,sum1++;continue; 47             case ‘V‘:b[i1]=5,sum1++;continue; 48             case ‘X‘:b[i1]=10,sum1++;continue; 49             case ‘L‘:b[i1]=50,sum1++;continue; 50             case ‘C‘:b[i1]=100,sum1++;continue; 51             case ‘D‘:b[i1]=500,sum1++;continue; 52             case ‘M‘:b[i1]=1000,sum1++;continue; 53             default: break; 54         } 55     } 56     if(sum1==1) 57         sum=b[0]; 58     else 59     { 60       sum=0; 61       for(i1=0;i1<sum1;i1++) 62       {   63           if(b[i1]>=b[i1+1]) 64               sum=sum+b[i1]; 65           else 66           { 67               sum=sum+(b[i1+1]-b[i1]); 68               i1++; 69           } 70       }  71     } 72     i=sum; 73     return sum; 74 } 75  76 istream& operator>>(istream&is,Roman_int&ri) 77 { 78     string s; 79     is>>s; 80     ri.as_int(s); 81     return is; 82 } 83  84 ostream& operator<<(ostream&os,Roman_int&ri) 85 { 86     return os<<ri.re_int(); 87 } 88  89 class Token_stream{ 90 public: 91     Token_stream(); 92     Roman_int get(); 93     Roman_int get(istream&); 94     void putback(Roman_int ri); 95 private: 96     bool full; 97     Roman_int buffer; 98 }; 99 100 Token_stream::Token_stream()101     :full(false),buffer(0)102 {103 }104 105 void Token_stream::putback(Roman_int t)106 {107     if(full) error("putback() into a full buffer");108     buffer=t;109     full=true;110 }111 112 Roman_int Token_stream::get(istream&ifs)113 {114     if(full){115         full=false;116         return buffer;117     }118     char ch;119     ifs>>ch;120     switch(ch){121     case ‘;‘: case ‘q‘: case ‘(‘: case ‘)‘: case ‘{‘:122     case ‘}‘:  case ‘+‘: case ‘-‘: case ‘*‘: case ‘/‘:123         return Roman_int(ch);124     case ‘I‘: case ‘V‘: case ‘X‘: 125     case ‘C‘: case ‘D‘: case ‘M‘:126         { 127             string s="";128             s+=ch;129             while(ifs>>ch)130             {131                 if(ch==‘I‘||ch==‘V‘||ch==‘X‘||ch==‘C‘||ch==‘D‘||ch==‘M‘)132                     s+=ch;133                 else134                 {135                     ifs.putback(ch);136                     break;137                 }138             }139             Roman_int r(‘8‘);140             r.as_int(s);141             return r;142         }143     case ‘f‘: 144         while(cin.get(ch)&&isalpha(ch))   145                 ;146             cin.putback(ch);147             return Roman_int(‘f‘);148     case ‘t‘:149             while(cin.get(ch)&&isalpha(ch))   150                 ;151             cin.putback(ch);152             return Roman_int(‘t‘);153     default:154         error("bad token");155         }156 }157 158 Token_stream ts;159 double expression(istream&ifs);160 161 double primary(istream&ifs)162 {163 164     Roman_int t=ts.get(ifs);165     switch(t.re_kind()){166     case ‘(‘:167     {168         int d=expression(ifs);169         t=ts.get(ifs);170         if(t.re_kind()!=‘)‘)  171             error("‘)‘expected");172         return d;173     }174     case ‘8‘:175         return t.re_int();176     default:177         error("primary expected",t.re_kind());178     }179 }180 181 double primary1(istream&ifs)182 {183     Roman_int t=ts.get(ifs);184     while(true)185     {186         switch(t.re_kind()){187         case ‘{‘:188         {189             double d=expression(ifs);190             t=ts.get(ifs);191             if(t.re_kind()!=‘}‘)  192                 error("‘}‘expected");193             return d;194         }195         default:196             ts.putback(t);197             return primary(ifs);198         }199     }200 }201 202 double term(istream&ifs)203 {204     double left=primary1(ifs);205     Roman_int t=ts.get(ifs);206 207     while(true){208         switch(t.re_kind()){209         case ‘*‘:210             left*=primary1(ifs);211             t=ts.get(ifs);212             break;213         case ‘/‘:214             {215                 double d=primary1(ifs);216                 if(d==0)217                     error ("divide by 0");218                 left /=d;219                 t=ts.get(ifs);220                 break;221             }222         default:223             ts.putback(t);224             return left;225         }226     }227 }228 229 double expression(istream&ifs)230 {231     double left=term(ifs);232     Roman_int t=ts.get(ifs);233     while(true){234         switch(t.re_kind()){235         case ‘+‘:236             left+=term(ifs);237             t=ts.get(ifs);238             break;239         case ‘-‘:240             left-=term(ifs);241             t=ts.get(ifs);242             break;243         default:244             ts.putback(t);245             return left;246         }247     }248 }249 250 int main()251 {252     try{253     double val=0;254     Roman_int t;255     while(cin)256     {257         t=ts.get(cin);258 259 260         if(t.re_kind()==‘f‘)261         {262             double val1=0;263             string s;264             cin>>s;265             ifstream ifs(s.c_str());266             if(!ifs)267                 error("can not open input file1",s);268             t=ts.get(cin);269             if(t.re_kind()==‘t‘)270             {271                 cin>>s;272                 ofstream ofs(s.c_str());273                 if(!ofs)274                     error("can not open output file1",s);275                 while(ifs)276                 {277                     t=ts.get(ifs);278                     while(t.re_kind()==‘;‘)279                         t=ts.get(ifs);280                     if(t.re_kind()==‘q‘) 281                         break;282                     ts.putback(t);283                     ofs<<as_roman(expression(ifs))<<endl;284                 }285             }286         }287         else288         {289 290             while(t.re_kind()==‘;‘)291                 t=ts.get(cin);292             if(t.re_kind()==‘q‘) 293             {294                 keep_window_open("~~");295                 return 0;        296             }        297             ts.putback(t);298             cout<<as_roman(expression(cin))<<endl;299         }300     }301     return 0;302 303     }304 305 catch(exception&e){306     cerr<<e.what()<<endl;307     while(1);308     return 1;309 }310 311 catch(...){312     cerr<<"exception\n";313     while(1);314     return 2;315 }316     317 }

 1 void fn(string&a,string&b,string&c) 2 { 3     ifstream ifs1(a.c_str()); 4     if(!ifs1) 5         error("can not open input file1",a); 6     ifstream ifs2(b.c_str()); 7     if(!ifs2) 8         error("can not open input file1",b); 9     vector<string> s;10     string ss;11     while(ifs1>>ss)12         s.push_back(ss);13     while(ifs2>>ss)14         s.push_back(ss);15     sort(s.begin(),s.end());//习题916     ofstream ofs(c.c_str());17     if(!ofs)18         error("can not open output file1",c);19     for(int i=0;i<s.size();i++)20         ofs<<s[i]<<‘ ‘;21 }

 1 #include "../../st.h" 2  3 int main() 4 { 5     string s1="a.txt"; 6     double sum=0; 7     double d; 8     char ch; 9     ifstream ifs(s1.c_str());10     if(!ifs)11         error("can not open input file1",s1);12     while(ifs>>ch)13     {14         if(isdigit(ch))15         {16             ifs.putback(ch);17             ifs>>d;18             sum+=d;19         }20     }21 22     cout<<sum<<endl;23     keep_window_open();24 }

 1 //用到第十一章内容 2  3 #include "../../st.h" 4  5 int main() 6 { 7     string s1="a.txt"; 8     string str1; 9     string s;10     int i=0;11     cout<<"input the word:";12     cin>>str1;13     ifstream ifs(s1.c_str());14     if(!ifs)15         error("can not open input file1",s1);16     while(getline(ifs,s))17     {18         i++;19         stringstream ss(s);20         string str;21         while(ss>>str)22         {23             if(str==str1){24                 cout<<i<<"    "<<s<<endl;25                 break;26             }27         }28 29     }30 31     keep_window_open();32 }