只是为了好玩，这里有相当多的修复。我不会一一列举。基本上：
- 通过引用传递固定大小的数组，以避免不安全的使用
- 严格检查输入错误，并在一个循环中完成
- 几个错误的数组赋值要么什么都不做，要么阻止调用者看到结果......
- 用于
char输入类型（因此Q会被匹配）并且更喜欢 aa 切换而不是重复的 ifs
- 请参阅下面的更典型的 C++ 样式解决方案，包括检查 WIN 或 LOSE
读者练习：为您的发电机播种rand()，或者赢得这张彩票非常简单（粘贴在上一张中奖彩票中:)）
演示运行的输出（也显示错误处理）：
LITTLETON CITY LOTTO MODEL:
---------------------------
1) Play Lotto
Q) Quit Program
Please make a selection: 1
Please enter your name: me
Please enter number 1:34
Please enter number 2:7
Please enter number 3:16
Please enter number 4:18
Please enter number 5:24
Please enter number 6:24
Duplicate entry 24
Please enter number 6:7
Duplicate entry 7
Please enter number 6:37
Please enter number 7:whoops
Bad input 'whoops' discarded
Please enter number 7:what was the last number again?
Bad input 'what' discarded
Please enter number 7:Bad input 'was' discarded
Please enter number 7:Bad input 'the' discarded
Please enter number 7:Bad input 'last' discarded
Please enter number 7:Bad input 'number' discarded
Please enter number 7:Bad input 'again?' discarded
Please enter number 7:27
User ticket: 7; 16; 18; 24; 27; 34; 37;
Winning ticket: 7; 16; 18; 24; 27; 34; 36;
Result of draw: WINNER
.
#include <string>
#include <iostream>
const size_t amount = 7;
void getLottoPicks(int (&ticket)[amount])
{
for(int i = 0; i < amount; i++)
{
do
{
std::cout << "\n Please enter number " << i + 1 << ":";
if(std::cin >> ticket[i])
{
if(ticket[i] >= 1 && ticket[i] <= 40)
{
bool ok = true;
for(int check = 0; ok && check < i; check++)
{
ok &= (ticket[i] != ticket[check]);
}
if(ok)
{
break;
}
else
{
std::cout << "You cannot use the same lotto number twice. Try again." << std::endl;
}
}
else
{
std::cout << "Your selection cannot be less than 1 and/or greater than 40. Try Again." << std::endl;
}
}
else
{
std::cin.clear();
std::string discard;
std::cin >> discard;
std::cout << "Bad input '" << discard << "' discarded";
}
}
while(true);
}
}
void GenWinNums(int (&winningNumbers)[amount])
{
for(int i = 0; i < amount; i++)
{
winningNumbers[i] = (rand() % 40) + 1;
while(winningNumbers[i] < 1 || winningNumbers[i] > 40)
{
winningNumbers[i] = (rand() % 10) + 1;
}
if(i > 0)
{
for(int check = 0; check < i; check++)
{
while(winningNumbers[i] == winningNumbers[check])
{
winningNumbers[i] = (rand() % 10) + 1;
}
}
}
}
}
int main()
{
std::string name;
char choice;
std::cout << "LITTLETON CITY LOTTO MODEL:" << std::endl;
std::cout << "---------------------------" << std::endl;
std::cout << " 1) Play Lotto " << std::endl;
std::cout << " Q) Quit Program " << std::endl;
std::cout << " Please make a selection: ";
std::cin >> choice;
switch(choice)
{
case '1':
{
std::cout << "\n Please enter your name: ";
std::cin >> name;
int user_picked[amount];
int chosen_lotto[amount];
getLottoPicks(user_picked);
GenWinNums(chosen_lotto);
std::cout << "\n";
for(int i = 0; i < amount; i++)
{
std::cout << user_picked[i] << "; ";
}
std::cout << "\n";
for(int i = 0; i < amount; i++)
{
std::cout << chosen_lotto[i] << "; ";
}
}
case 'Q':
case 'q':
return 0;
default:
std::cout << "\n That is not a valid choice." << std::endl;
}
std::cout << "\n Press enter...";
std::cin >> choice;
}
比较典型的C++方案
#include <string>
#include <iostream>
#include <algorithm>
#include <iterator>
#include <set>
const size_t amount = 7;
typedef std::set<int> ticket_t;
ticket_t getLottoPicks()
{
ticket_t ticket;
while (ticket.size() < amount)
{
std::cout << "\n Please enter number " << (ticket.size()+1) << ":";
int entry;
if(std::cin >> entry)
{
if(entry >= 1 && entry <= 40)
{
if (ticket.end() != ticket.find(entry))
std::cout << "Duplicate entry " << entry;
else
ticket.insert(entry);
} else
std::cout << "Entry out of range [1..40]: " << entry;
continue;
}
std::cin.clear();
std::string discard;
std::cin >> discard;
std::cout << "Bad input '" << discard << "' discarded";
}
return ticket;
}
ticket_t genWinNums()
{
ticket_t ticket;
while (ticket.size() < amount)
ticket.insert(rand() % 40 + 1);
return ticket;
}
std::ostream& operator<<(std::ostream& os, ticket_t const& t)
{
std::copy(t.begin(), t.end(), std::ostream_iterator<int>(os, "; "));
return os;
}
int main()
{
std::cout << "LITTLETON CITY LOTTO MODEL:" << std::endl;
std::cout << "---------------------------" << std::endl;
std::cout << " 1) Play Lotto " << std::endl;
std::cout << " Q) Quit Program " << std::endl;
std::cout << "Please make a selection: ";
char choice;
std::cin >> choice;
switch(choice)
{
case '1':
{
std::cout << "\n Please enter your name: ";
std::string name;
std::cin >> name;
const ticket_t user = getLottoPicks();
const ticket_t winning = genWinNums();
std::cout << "User ticket: " << user << "\n";
std::cout << "Winning ticket: " << winning << "\n";
// check win?
bool ok = 0 == std::lexicographical_compare(
user.begin(), user.end(),
winning.begin(), winning.end());
std::cout << "Result of draw: " << (ok? "WINNER":"No luck") << "\n";
}
case 'Q': case 'q':
return 0;
default:
std::cout << "\n That is not a valid choice." << std::endl;
}
std::cin.ignore(1<<24,'\n');
std::cout << "\n Press enter...";
std::string dummy;
std::getline(std::cin, dummy);
}