**
**：#includenamespace pers { struct person { std::string fname; std::string lname;}; void getperson(person&); void show(const person&);} namespace debts { using namespace pers; struct debt { person name; double amount; }; void getdebt(debt&); void showdebt(const debt&); double sum(const debt ar[], int n);}源文件（两个）：第一个：通过包含头文件，导入了原来的名称空间，然后该文件将函数定义添加到两个名称空间中。#include #include “源.cpp"using namespace debts; namespace pers { using std::cout; using std::cin; void getperson(person& rp) { cout << “enter fname”; cin >> rp.fname; cin >> rp.lname; } void show(const person & rp) { cout << rp.fname; cout << rp.lname << “\t”; } } namespace debts {void getdebt(debt&rp) { getperson(rp.name); cout << “please enter debt”; cin >> rp.amount;} void showdebt(const debt&rp) { show(rp.name); cout << rp.amount; }double sum(const debt ar[], int n) { double am = 0; for (int i = 0; i < n; i++) am += ar[i].amount; return am; }}第二个：含有主函数main#include #include"源.cpp” void other(void); void another(void); using namespace std; using namespace pers; using namespace debts; int main() { debt golf = { {“ben”,“jieming”},32.1 }; showdebt(golf); other();} void other() { person dg = { “ii”,“derw” }; show(dg); cout << endl; debt dogg[3]; int i; for (i = 0; i < 3; i++) getdebt(dogg[i]); for (i = 0; i < 3; i++) showdebt(dogg[i]); cout << “tatol debt $” << sum(dogg, 3);}
include double x; int main() { std::cout << “enter!”;
while (!(std::cin >> x)) { std::cout << “should double”; std::cin.clear(); while (std::cin.get() != ‘\n’) continue; } std:: cout << “the value is” << x; }
include using namespace std; enum color{red,blue,green}; enum color pri; int n,i, j, k, loop; int main() { n = 0; for (i = red ;i <= green ;i++) for (j = red; j <= green; j++) { for (k = red; k <= green; k++) if (i != j) { if ((k != i) && (k != j)) { n++; cout << n << “:”; for (loop = 1; loop <= 3; loop++) { switch (loop) { case(1):pri = (enum color)i; break; case(2):pri = (enum color)j; break; case(3):pri = (enum color)k; break; } switch (pri) { case(red):cout << "red "; break; case(blue):cout << "blue "; break; case(green):cout << "green "; break; }
} cout << endl; } } }。#includeusing namespace std; void move(int p[], int n) { int t; t = p[n - 1]; if (n == 0) return; for (int i = n-1; i > 0; i–)//注意i的取值 { p[i] = p[i - 1]; } p[0] = t;} void movep(int p[], int k, int n) { for (int i = 0; i < k; i++) move(p, n);//调用move函数移动k位 } int main() { int p[5]; int n; cin >> n; for (int i = 0; i < n; i++) { cin >> p[i]; } for (int i = 0; i < n; i++) { cout << p[i]; } int k; cout << “the k:”; cin >> k; movep(p, k, n); cout << “after:”; for (int i = 0; i < n; i++) cout << p[i];}
（有待思考)#define _CRT_SECURE_NO_WARNINGS #include #include #includeusing namespace std; void index(char* s1, char* s2) { int len ,max = 0; char temp[50]; while (*s1) { while (*s1 == ’ ’ && *s1 != ‘\0’) s1++;//过滤空格；
len = 0; while (*s1 != ' ' && *s1 != '\0') { *(temp + len) = *s1;//不能用*temp=*s1,why? len++; s1++; } *(temp + len) = '\0';//注意这种方式。 if (len > max) { max = len; strcpy(s2, temp); } if (*s1 == '\0') break;}} int main() { char s1[50],s2[50];cin.get(s1,50); index(s1, s2); cout << “s2:” << s2; }用队列的方法输出杨辉三角：#include using namespace std; const int maxsize = 100; typedef struct { int Q[maxsize];//存放数据 int front, rear; }sequeue; sequeue qu; void setkong(sequeue& qq) { qq.front = 0; qq.rear = 0; }//置队空 void rudui(sequeue& qq, int x) { if (qq.front == (qq.rear + 1) % maxsize) cout << “overflow\n”; else { qq.Q[qq.rear] = x; qq.rear = (qq.rear + 1) % maxsize; } } void chudui(sequeue &qq, int& x) { if (qq.front == qq.rear) { cout << “underflow\n”; } else { x = qq.Q[qq.front]; qq.front = (qq.front + 1) % maxsize; } } void getfront(sequeue qq, int &x)//读取队头元素 { if (qq.front == qq.rear) { cout << “error!\n”; } else { x = qq.Q[qq.front]; } } int empty(sequeue qq)//判断队列是否为空 { if (qq.front == qq.rear) return 1; else return 0; } void yanghui(int n,sequeue qu) { int i, j,s,t; setkong(qu); rudui(qu, 1); rudui(qu, 1); cout << endl; cout.width(4); cout << 1; cout.width(4); cout << 1<<endl; for (i = 2; i <= n; i++)//生成并输出杨辉三角第i~n行的数据 { rudui(qu, 1); cout.width(4); cout << 1; chudui(qu, s); for (j = 2; j <= i; j++)//处理第i行中间的各数据 { chudui(qu, t); rudui(qu, s + t); cout.width(4); cout << s + t; s = t;
} rudui(qu, 1); cout.width(4); cout << 1<<endl; } cout << endl; } int main() { int m; cin >> m; yanghui(m, qu); }
include #include #include<unordered_set> using namespace std; int lengthOfLongestSubstring(string s); int lengthOfLongestSubstring(string s) { // 哈希集合，记录每个字符是否出现过 unordered_set occ; int n = s.size(); // 右指针，初始值为 -1，相当于我们在字符串的左边界的左侧，还没有开始移动 int rk = -1, ans = 0; // 枚举左指针的位置，初始值隐性地表示为 -1 for (int i = 0; i < n; ++i) { if (i != 0) { // 左指针向右移动一格，移除一个字符 occ.erase(s[i - 1]); } while (rk + 1 < n && !occ.count(s[rk + 1])) { // 不断地移动右指针 occ.insert(s[rk + 1]); ++rk; } // 第 i 到 rk 个字符是一个极长的无重复字符子串 ans = max(ans, rk - i + 1); } return ans; }; int main() { string mm; cin >> mm; int num; num = lengthOfLongestSubstring(mm); cout << num; }
（二维数组初始化)//彩票案例 //随机生成1-49之间的苏子 程序中每一组中按照升序排序 //检查某个数字在用户选择的所有彩票中出现的次数 //七行六列随机数 //注意初始化二维数组 int table = new int**[7] //int table[i] = new int*[6] //下标越界时会导致错误 #include #include #include using namespace std; const int column = 6; const int maxx = 49; void iniarray(int**, int); int isnum(int**, int, int); void sort(int**, int); void print(int**); int numoccur(int** table, int mm); inline void memerror() { cout << “error\n”; exit(1); } void genloto(int**, int); int main() { int** table; int numcheck; int i; int client; char answer; srand((unsigned)time(0)); table = new int* [7]; if (!table) memerror(); for (i = 0; i < 7; i++) { table[i] = new int[6]; if (!table[i]) memerror();//check for an allocation error } iniarray(table, 7); genloto(table, 7); for (i = 0; i < 7; i++) { sort(table, i);//sort numbers in a row } print(table); cin >> client;//用户输入数字 numcheck = numoccur(table, client); cout << "the num = " << numcheck; } void iniarray(inttable, int) { int i, j; for (i = 0; i < 7; i++) { for (j = 0; j < 6; j++) table[i][j] = 0; } } void genloto(inttable, int) { int i, j; int newnum; for (i = 0; i < 7; i++) { for (j = 0; j < 6; j++) { do { newnum = rand() % maxx + 1; } while (isnum(table, i, newnum)); table[i][j] = newnum; } } } int isnum(int**table, int num, int n) { for (int i = 0; i < 6; i++) { if (table[num][i] == 0) return 0; if (table[num][i] == n) return 1; } return 0; } //
void sort(int** table, int row) { int temp; for (int i = 0; i < 5; i++) {//注意i j 一定不能大于5 for (int j = 0; j < 5; j++) { if (table[row][j] > table[row][j + 1]) { temp = table[row][j]; table[row][j] = table[row][j + 1]; table[row][j + 1] = temp; } } } } void print(inttable) { cout << endl; cout << "**\n"; for (int i = 0; i < 7; i++) { for (int j = 0; j < 6; j++) cout << table[i][j] << “\t”; cout << endl; } } int numoccur(int table, int num) { int count = 0; for (int i = 0; i < 7; i++) { for (int j = 0; j < 6; j++) { if (table[i][j] == num) count++; } } return count; }
include #include using namespace std; class saving { private: int id; double balance;//余额 double rate;//年利率 int lastdate;//上次变更余额的时期 double accumulation;//余额按日期累加之和 void record(int date, double amount); double accumulate(int date) const { return accumulation + balance * (date - lastdate); } public: saving(int date, int id, double rate);//构造函数 int getid() { return id; } double getbalance() { return balance; } double getrate() { return rate; } void deposit(int date, double amount);//存入现金 void withdraw(int date, double amount);//取出现金 void settle(int date);//结算利息 void show();//显示账号信息 }; saving::saving(int date, int id, double rate):id(id),balance(0),rate(rate),lastdate(date),accumulation(0) { cout << id << “is created\n”; } void saving::record(int date, double amount) { accumulation = accumulate(date); lastdate = date; amount = floor(amount * 100 + 0.5) / 100; //保留小数点后两位 balance += amount; cout << date << “—” << id <<“amount:”<< amount<<“balance:” << balance;
} void saving::deposit(int date, double amount) { record(date, amount);
} void saving:: withdraw(int date, double amount) { if (getbalance() < 0) cout << “error\n”; else record(date, -amount); } void saving:: settle(int date) { double interest = accumulate(date) * rate / 365; if (interest != 0) record(date, interest); accumulation = 0; } void saving::show() { cout << id << balance; } int main() { saving s1(1, 4234, 0.15); s1.deposit(3, 5000); s1.show(); s1.deposit(5, 3000); cout << endl; s1.show(); cout << endl; s1.settle(80); s1.show(); cout << endl; } 容器嵌套#include
#include #include using namespace std; void test() { vector<vector> mm; vectorp1; vectorp2; vectorp3; vectorp4; for (int i = 0; i < 4; i++) { p1.push_back(i); p2.push_back(i + 1); p3.push_back(i + 2); p4.push_back(i + 3); } mm.push_back(p1); mm.push_back(p2); mm.push_back(p3); mm.push_back(p4); for (vector<vector>::iterator mg = mm.begin(); mg != mm.end(); mg++)
{ for (vector<int>::iterator yj = (*mg).begin(); yj != (*mg).end(); yj++) cout << *yj; cout << endl; }} int main() { test(); } 访问单个字符:string str = “hello”;for(int i = 0;i < str.size() ;i++)cout<<str[i];
include
class function//抽象类function的定义 { public: virtual double operator()(double x) const = 0;//纯虚函数重载运算符（） virtual ~function() {}; }; class myfunction :public function { public: double operator()(double x) const;//覆盖虚函数 }; class integrate { public: virtual double operator()(double a, double b, double eps)const = 0; virtual ~integrate() {} }; class grate :public integrate { public: double operator()(double a, double b, double eps)const; grate(function&mm):f(mm){}//构造函数 private: function& f;//私有成员 }; //类实现 double myfunction::operator()(double x) const { return log(1.0 + x) / (1.0 + x * x); } double grate::operator()(double a, double b, double eps)const { myfunction yy; grate nice(yy); bool judge = false; double h = b - a; double tn = (yy(a) + yy(b)) * h / 2; double t2n; int n = 1; do{ double sum = 0; for (int k = 0; k < n; k++) { double x = a + (k + 0.5) * h; sum += f(x); } t2n = (tn + h * sum) / 2.0;//变步长梯形法计算 if (fabs(t2n - tn) < eps)//判断积分误差 judge = true; else { tn = t2n; n *= 2; h /= 2; } } while (!judge); return t2n;
}
#include template class Array { T* mm;//T类型指针 用于存放动态分配的数组首地址 int size;//数组大小 public: Array(int siz = 50); Array(const Array& yy);//复制构造函数 ~Array(); Array& operator = (Array& rhs);//重载“=” T& operator [](int i);//重载[]; operator T* (); //重载指针转化运算符T* 要想对象名能像数组名一样使用下标，还要重载下标运算符 int getsize()const; void resize(int sz);//修改数组大小 }; template Array::Array(int siz) { assert(siz >= 0); size = siz; mm = new T[size];//动态分配size个T类型的元素空间 } template Array& Array:: operator = (Array& rhs) //重载“=” 将对象rhs赋给本对象 实现对象之间整体赋值 { if (size != rhs.size) {//如果本对象中数组大小与rhs不同 则删除数组原有内存然后重新分配
delete[]mm;//删除数组原有内存 size = rhs.size;//设置本对象数组大小 mm = new T[size];//重新分配size个元素的内存 } for (int i = 0; i < size; i++) { mm[i] = rhs.mm[i]; } return *this;//返回当前对象的引用} template Array::~Array() { delete[]mm; } template Array::operator T* () { return mm;//返回当前对象中私有数组的首地址 }
template T& Array:: operator [] (int i) { assert(i >= 0 && i < size);//检查下标是否越界 return mm[i]; } template int Array::getsize()const { return size; } template void Array::resize(int sz) { assert(sz >= 0);//检查sz是否非负 if (size == sz) return;//如果指定的大小与原有大小一样什么也不做 T* newlist = new T[sz];//申请新的内存 int n = (sz < size) ? sz : size;//将sz 与size中较小的值赋给n for (int i = 0; i < n; i++) { newlist[i] = mm[i];//将原有数组的前n个元素复制到新数组中 } delete[] mm;//删除原数组 mm = newlist;//使mm指向新数组 size = sz;//更新size
}
：#include #include"trap.h" #include
using namespace std; int main() { int n; cin >> n; int count = 0; Arraynice(10); int i;
for (i = 2; i < n; i++) {//检查i能否被比它小的质数整除 bool judge = true; for (int j = 0; j < count; j++)//如果i被nice[j]整除说明i不是质数 { if (i % nice[j] == 0) { judge = false; break; } } if (judge) { if (count == nice.getsize())//如果质数表满了将其空间加倍 nice.resize(count * 2); nice[count++] = i; } } for (i = 0; i < count; i++) cout <<setw(8)<< nice[i];}//个人认为a[0]一开始应该是一个随机数
#include #include #include #include #include using namespace std; int main() { istream_iterators1(cin), s2;//建立一对输入流迭代器 vector i1(s1, s2);//通过输入流迭代器从标准输入流中输入数据 sort(i1.begin(), i1.end());//将输入的整数排序 dequem1; //循环遍历i1 for (vector::iterator ite = i1.begin(); ite != i1.end(); ++ite) { if (*ite % 2 == 0)//偶数放m1尾部 m1.push_back(*ite); else m1.push_front(*ite); } copy(m1.begin(), m1.end(), ostream_iterator(cout, “-”));//输出结果 以-符号分隔 } 结点类模板#include
using namespace std; //结点类模板 template class node { private: node* next;//指向后继结点的指针 public: T data;//数据域 node(const T& data, node* next = 0);//构造函数 void insert(node* p);//在本结点之后插入一个同类结点 node* deleteafter();//删除本结点的后继结点并且返回其地址 node* getlocation();//获取后继结点的地址 const node* getlocation() const;//获取后继结点的地址 }; //类的实现部分 template node::node(const T& data, node* next ):data(data),next(next){} template void node::insert(node* p) { p->next = next;//p的指针域指向当前结点的后继结点 next = p;//当前结点指针域指向p
} template nodenode:: deleteafter() { node temp; temp = next;//将欲删除的结点地址存储在temp中 if (next == 0)//如果当前结点没有后继结点 返回空指针 return 0; next = temp->next;//使当前结点指向temp的后继结点 return temp;//返回被删除的结点的地址 } template node* node::getlocation() { return next;//返回后继结点的指针 } template const node* node::getlocation() const { return next; }
:#include #include #include #include using namespace std; const int maxx = 2000; const int minn = 500; class cell; priority_queuecellque;
class cell { private: static int total;//细胞总数 int id;//当前细胞编号 int time;//细胞分裂时间 public: cell(int birth) :id(total++) { time = birth + (rand() % (maxx - minn) )+ minn; } //初始化获得细胞分裂时间 int getid() const{ return id; }//获取细胞编号 int gettime() const{ return time; }//获取细胞分裂时间 bool operator <(const cell& s)const { return time > s.time; }//定义"<" void spilit()const { cell xibao1(time), xibao2(time);//得到两个细胞 cout << time << “cell” << id << “splits to” << xibao1.getid() << " " << xibao2.getid() << endl; cellque.push(xibao1);//将第一个子细胞压入优先级队列 cellque.push(xibao2);//
}}; int cell::total = 0; int main() { srand(static_cast(time(0))); int t; cout << “input\n”; cin >> t; cellque.push(cell(0)); while (cellque.top().gettime() <= t) { cellque.top().spilit(); cellque.pop(); } } //栈操作#include #include using namespace std; template<class T, int size = 50> class stack { private: T list[size]; int top; public: stack(); void push(const T& mm){ assert(!isfull());//如果栈满了则报错 list[++top] = mm;//将新元素压入栈顶
} T pop()//将栈顶元素弹出栈 { assert(!isempty()); return list[top–];//返回栈顶元素并将其弹出栈 } void clear() { top = -1;//清空栈 } const T& peek()const//访问栈顶元素 { assert(!isempty());//如果为空则报错 return list[top]; } bool isempty()const { return top == -1; }
bool isfull()const { return top == size - 1; } }; template<class T, int size> stack<T, size>::stack() :top(-1) {};//构造函数 栈顶初始化为-1.class cal { stacks; void enter(double num) { s.push(num); }//操作数弹出栈 如果栈中没有两个操作数则返回错误信息 bool gettwo(double& o1, double& o2) { bool mod; if (s.isempty()) { cout << “error”; mod = false; } else o1 = s.pop(); if (s.isempty()) mod = false; else { o2 = s.pop(); mod = true; } } void ope(char op)//连续将两个操作数弹出并放在o1和o2中 如果成功 执行运算并将结果压入栈 { double oo1, oo2; bool result = gettwo()}//执行由操作符op指定的运算 public: void run() void clear() };
