//question1
#include <iostream>
#include <string>
bool is_circle(const std::string & s);
int main() {
std::string s;
std::cout << "Enter a word(q to quit): \n";
while(std::cin >> s && s != "q")
{
if(is_circle(s))
std::cout << "Yes, it's huiwen.\n";
else
std::cout << "No, it's not.Try again.\n";
std::cout << "Enter a word(q to quit): \n";
}
return 0;
}
bool is_circle(const std::string & s)
{
std::string s_temp(s);
reverse(s_temp.begin(), s_temp.end());
if(s != s_temp)
return false;
else
return true;
}
//question2
#include <iostream> #include <algorithm> #include <cctype> #include <string>
bool is_circle(std::string & s);
int main() {
std::string s; std::cout << "Enter a word(q to quit): \n"; while(getline(std::cin, s) && s != "q") { if(is_circle(s)) std::cout << "Yes, it's huiwen.\n"; else std::cout << "No, it's not.Try again.\n"; std::cout << "Enter a word(q to quit): \n"; } return 0; }
bool is_circle(std::string & s) { std::string::iterator pd; for(pd = s.begin(); pd != s.end(); ) { if(!isalpha(*pd) || isspace(*pd)) s.erase(pd); //查了半天才发现erase返回下一个迭代器，所以不能在for循环中统一进行pd++，否则会跳过一些字符 else { *pd = tolower(*pd); pd++; } } std::string s_temp(s); std::cout << s << std::endl; reverse(s_temp.begin(), s_temp.end()); if(s != s_temp) return false; else return true; }
//question3
#include <iostream> #include <fstream> #include <string> #include <cstdlib> #include <ctime> #include <vector> #include <cctype>
using std::string;
int main() { using std::cout; using std::cin; using std::tolower; using std::endl; std::srand(std::time(0)); char play; std::ifstream ifs; ifs.open("wordlist.txt", std::ifstream::in); std::string word; std::vector<string> wordlist; if(ifs.good()) { while(ifs >> word) wordlist.push_back(word); } int length = wordlist.size(); cout << "Will you play a word game? <y/n>"; cin >> play; play = tolower(play); while(play == 'y') { string target = wordlist[std::rand() % wordlist.size()]; int length = target.length(); string attempt(length, '-'); string badchars; int guesses = 6; cout << "Guess my secret word. It has " << length << " letters, and you guess\n" << "one letter at a time. You get " << guesses << " wrong guesses.\n"; cout << "Your word: " << attempt << endl; while(guesses > 0 && attempt != target) { char letter; cout << "Guess a letter: "; cin >> letter; if (badchars.find(letter) != string::npos || attempt.find(letter) != string::npos) { cout << "You already guessed that. Try again\n"; continue; } int loc = target.find(letter); if (loc == string::npos) { cout << "Oh, bad guess!\n"; --guesses; badchars += letter; } else { cout << "Good guess!\n"; attempt[loc] = letter; loc = target.find(letter, loc + 1); while(loc != string::npos) { attempt[loc] = letter; loc = target.find(letter, loc + 1); } } cout << "Your word: " << attempt << endl; if(attempt != target) { if(badchars.length() > 0) cout << "Bad choices: " << badchars << endl; cout << guesses << " bad guesses left\n"; } } if(guesses > 0) cout << "That's right!\n"; else cout << "Sorry, the word is " << target << ".\n"; cout << "Will you play another? <y/n>"; cin >> play; play = tolower(play); } cout << "Bye\n"; ifs.close(); return 0; }
//question4
#include <iostream> #include <algorithm> #include <set> #include <iterator> //#include <string>
int reduce(long ar[], int n); int main() { long ar1[5] = {45000, 3400, 45000, 100000, 2500}; int resize = reduce(ar1, 5); std::cout << "array1: \n"; for (int i = 0; i < resize; i++) { std::cout << ar1[i] << " "; } return 0; }
int reduce(long ar[], int n) { std::set<long> arrayset; int i; for (i = 0; i < n; i++) arrayset.insert(arrayset.end(), ar[i]); auto pd = arrayset.begin(); for (i = 0; i < arrayset.size(); i++, pd++) ar[i] = *pd; return arrayset.size(); }
//question5
#include <iostream> #include <algorithm> #include <set> #include <iterator> #include <string>
template <typename T> int reduce(T ar[], int n) { std::set<T> arrayset; int i; for (i = 0; i < n; i++) arrayset.insert(arrayset.end(), ar[i]); auto pd = arrayset.begin(); for (i = 0; i < arrayset.size(); i++, pd++) ar[i] = *pd; return arrayset.size(); }
int main() { long ar1[5] = {45000, 3400, 45000, 100000, 2500}; int resize = reduce(ar1, sizeof(ar1)/sizeof(long)); std::cout << "array1: \n"; int i; for (i = 0; i < resize; i++) { std::cout << ar1[i] << " "; } std::string ar2[6] = {"it", "aboard", "it", "zone", "quit", "aa"}; resize = reduce(ar2, sizeof(ar2)/sizeof(std::string)); std::cout << "\narray2: \n"; for (i = 0; i < resize; i++) { std::cout << ar2[i] << " "; } return 0; }
//question6
//16_6.cpp #include "customer.h" #include <iostream> #include <queue> #include <cstdlib> #include <ctime> const int MIN_PER_HR = 60;
bool newcustomer(double x);
int main() { using std::cin; using std::cout; using std::endl; using std::ios_base; std::srand(std::time(0)); cout << "Case Study: Bank of Heather Automatic Teller\n"; cout << "Enter maximum size of queue: "; int qs; cin >> qs; std::queue<Item> line; cout << "Enter the average number of customers per hour: "; int hours; cin >> hours; long cyclelimit = MIN_PER_HR *hours; cout << "Enter the average number of customers per hour: "; double perhour; cin >> perhour; double min_per_cust; min_per_cust = MIN_PER_HR / perhour; Item temp; long turnaways = 0; long customers = 0; long served = 0; long sum_line = 0; int wait_time = 0; long line_wait = 0; for (int cycle = 0; cycle < cyclelimit; cycle++) { if (newcustomer(min_per_cust)) { if (line.size() == qs) turnaways++; else { customers++; temp.set(cycle); line.push(temp); } } if (wait_time <= 0 && !line.empty()) { temp = line.front(); wait_time = temp.ptime(); line.pop(); line_wait += cycle - temp.when(); served++; } if (wait_time > 0) wait_time--; sum_line += line.size(); } if (customers > 0) { cout << "customers accepted: " << customers << endl; cout << " customers served: " << served << endl; cout << " turnaways: " << turnaways << endl; cout << "average queue size: "; cout.precision(2); cout.setf(ios_base::fixed, ios_base::floatfield); cout << (double) sum_line / cyclelimit << endl; cout << " average wait time: " << (double) line_wait / served << " minutes\n"; } else cout << "No customers!\n"; cout << "Done!\n"; return 0; }
bool newcustomer(double x) { return (std::rand() * x / RAND_MAX < 1); }
//customer.h #ifndef CUSTOMER_H #define CUSTOMER_H #include <cstdlib>
class Customer { private: long arrive; int processtime; public: Customer() {arrive = processtime = 0;} void set(long when); long when() const {return arrive;} int ptime() const {return processtime;} };
void Customer::set(long when) { processtime = std::rand() % 3 + 1; arrive = when; } typedef Customer Item; #endif
//question7
#include <iostream> #include <vector> #include <algorithm>
std::vector<int> Lotto(int a, int b);
int main() { std::vector<int> winners; winners = Lotto(51,6); std::vector<int>::iterator pd; std::cout << "winners: \n"; for (pd = winners.begin(); pd != winners.end(); pd++) std::cout << *pd << " "; return 0; }
std::vector<int> Lotto(int a, int b) { std::vector<int> list, win; for(int i = 0; i < b; i++) { for(int j = 0; j < a; j++) list.push_back(j+1); std::random_shuffle(list.begin(), list.end()); win.push_back(*list.begin()); } return win; }
//question8
#include <iostream> #include <set> #include <string> #include <algorithm> int main() { std::cout << "Enter Mat's friends(q to quit): \n"; std::string name; std::set<std::string> namelist_Mat, namelist_Pat, common; std::set<std::string>::iterator pd; while(std::cin >> name && name != "q") namelist_Mat.insert(name); std::cout << "\nMat's friends are: \n"; for(pd = namelist_Mat.begin(); pd != namelist_Mat.end(); pd++) std::cout << *pd << " "; std::cout << "\nEnter Pat's friends(q to quit): \n"; while(std::cin >> name && name != "q") namelist_Pat.insert(name); std::cout << "\nPat's friends are: \n"; for(pd = namelist_Pat.begin(); pd != namelist_Pat.end(); pd++) std::cout << *pd << " "; std::set_union(namelist_Mat.begin(),namelist_Mat.end(),namelist_Pat.begin(), namelist_Pat.end(), inserter(common, common.begin())); std::cout << "\nInvited friends are: \n"; for(pd = common.begin(); pd != common.end(); pd++) std::cout << *pd << " "; return 0; }
//question9
#include <iostream> #include <ctime> #include <vector> #include <list> #include <stdlib.h> #include <algorithm>
int main() { srand (time(NULL)); std::vector<int> vi0; for(int i = 0; i < 1000000; i++) vi0.push_back(rand()); std::vector<int> vi(vi0); std::list<int> li(vi0.begin(), vi0.end()); clock_t start = clock(); std::sort(vi.begin(), vi.end()); clock_t end = clock(); std::cout << "Sort the vector: "; std::cout << (double)(end - start) / CLOCKS_PER_SEC << "\n"; start = clock(); li.sort();//忘了stl中sort不能直接用于list，只能用list自带的sort函数 end = clock(); std::cout << "Sort the list: "; std::cout << (double)(end - start) / CLOCKS_PER_SEC << "\n"; li.assign(vi0.begin(), vi0.end()); start = clock(); vi.assign(li.begin(), li.end()); std::sort(vi.begin(), vi.end()); li.assign(vi.begin(), vi.end()); end = clock(); std::cout << "Time: "; std::cout << (double)(end - start) / CLOCKS_PER_SEC << "\n"; return 0; }
//question10
#include <iostream> #include <string> #include <vector> #include <algorithm> #include <memory> //shared_ptr
struct Review { std::string title; int rating; int price; };
bool operator<(const std::shared_ptr<Review> & p1, const std::shared_ptr<Review> & p2); bool ratingup_com(const std::shared_ptr<Review> & p1, const std::shared_ptr<Review> & p2); bool ratingdown_com(const std::shared_ptr<Review> & p1, const std::shared_ptr<Review> & p2); bool priceup_com(const std::shared_ptr<Review> & p1, const std::shared_ptr<Review> & p2); bool pricedown_com(const std::shared_ptr<Review> & p1, const std::shared_ptr<Review> & p2); bool FillReview(Review & rr); void ShowReview(const std::shared_ptr<Review> & p);
int main() { using namespace std; vector<shared_ptr<Review> > books; Review temp; while(FillReview(temp)) { shared_ptr<Review> pd (new Review(temp)); books.push_back(pd); } if (books.size() > 0) { cout << "Please choose the way to sort: " << "n: normal, a: alpha, r: rating(up), s: rating(down), p: price(up), d: price(down), q: quit\n"; char a; while(cin >> a && a != 'q') { switch(a) { // case "n": sort(books.begin(), books.end()); // break; // case "a": sort(books.begin(), books.end()); // break; case 'r': sort(books.begin(), books.end(), ratingup_com); break; case 's': sort(books.begin(), books.end(), ratingdown_com); break; case 'p': sort(books.begin(), books.end(), priceup_com); break; case 'd': sort(books.begin(), books.end(), pricedown_com); break; default: sort(books.begin(), books.end()); break; } for_each(books.begin(), books.end(), ShowReview); cout << "Please choose the way to sort: " << "n: normal, a: alpha, r: rating(up), s: rating(down), p: price(up), d: price(down), q: quit\n"; } } return 0; }
bool FillReview(Review & rr) { std::cout << "Enter book title (quit to quit): "; std::getline(std::cin, rr.title); if (rr.title == "quit") return false; std::cout << "Enter book rating: "; std::cin >> rr.rating; if (!std::cin) return false; std::cout << "Enter book price: "; std::cin >> rr.price; if (!std::cin) return false; while (std::cin.get()!='\n') continue; return true; }
void ShowReview(const std::shared_ptr<Review> & p) { std::cout << p->rating << "\t" << p->title << "\t" << p->price << std::endl; }
bool operator<(const std::shared_ptr<Review> & p1, const std::shared_ptr<Review> & p2) { if (p1->title < p2->title) return true; else if (p1->title == p2->title && p1->rating < p2->rating) return true; else return false; }
bool ratingup_com(const std::shared_ptr<Review> & p1, const std::shared_ptr<Review> & p2) { if (p1->rating < p2->rating) return true; else return false; }
bool ratingdown_com(const std::shared_ptr<Review> & p1, const std::shared_ptr<Review> & p2) { if (p1->rating > p2->rating) return true; else return false; }
bool priceup_com(const std::shared_ptr<Review> & p1, const std::shared_ptr<Review> & p2) { if (p1->price < p2->price) return true; else return false; }
bool pricedown_com(const std::shared_ptr<Review> & p1, const std::shared_ptr<Review> & p2) { if (p1->price > p2->price) return true; else return false; }
