從2中2然後3中計數

Question

我把這作爲我的IT作業 「一隻猴子打開N個儲物櫃。然後，他從儲物櫃1開始，並從2入2關閉儲物櫃（例如：1關閉，2是開放的，3是封閉的，4是開放的），然後他再次做同樣的事情，但在3中是3。如果他碰到一個封閉的儲物櫃，他會打開它，他這樣做了N次。問題想知道哪些儲物櫃保持打開狀態。

有一個N = 10的例子，結果是2,5,10。 我做錯了什麼？

//NOTE : 1-OPEN, 0-Closed 
    int a[10],n,i,j,k=2; 
    cout<<"Cate colivii exista? ";cin>>n; 
    for(i=0; i<n; i++) 
    { 
     a[i]=1; 
    } 
    for(i=0; i<n; i=i+k) 
     { 
      if(a[i]==1) 
       a[i]=0; 
      else if(a[i]==0) 
       a[i]=1; 
      k++; 
     } 
    for(i=0; i<n; i++) 
    { 
     if(a[i]==1) 
      cout<<i<<" "; 
    } 
//K should have been a number but i changed it. 
    return 0; 
} 

Answer 1

我重寫它，以改善一些東西放在一起，交換空調風格的C++風格

#include<iostream> 
#include<vector> 
using std::cout; //not using namespace std since that one is too big 
using std::endl; 
using std::vector; 

//declaring but not implementing here, want only to describe what it does here, not how 
//at this place, you might want to write a comment that describes what the function does 
void locker_monkey(const unsigned int amount_lockers); 

//keeping the main function simple 
int main() { 

    //initializing every variable if possible, 
    //also using unsigned int since it should never be negative 
    unsigned int amount_lockers = 0; 
    cout << "Cate colivii exista? "; 
    cin >> amount_lockers; 

    locker_monkey(amount_lockers); 

    return 0; 
} 

enum LockerStatus{ closed, open }; //using enum to make values descriptive 

void locker_monkey(const unsigned int amount_lockers){ 

    //use std::vector instead of array 
    //if created with two arguments, the first is the size of the vector, 
    //the second the default value 
    vector<LockerStatus> lockers_status(amount_lockers, open); 

    //here comes the important part regarding your question, two loops: 
    for(unsigned int k=2; k<amount_lockers; k++){ //outer one increases k 
     for(unsigned int i=0; i<amount_lockers; i+=k){ //inner one increases i 
      if(lockers_status[i] == open){ //more descriptive that a[i] == 1 
       lockers_status[i] = closed; 
      }else{ 
       lockers_status[i] = open; 
      } 
     } 
    } 

    cout << "open lockers: "; 
    for(unsigned int i=0; i<amount_lockers; i++){ 
     if(lockers_status[i]==open) 
     cout<<i<<" "; 
    } 
    cout << endl; //you forgot that part in your code - you want to finish your line 
} 

的重要組成部分，是建立在雙循環，即

for(unsigned int k=2; k<amount_lockers; k++){ 
     for(unsigned int i=0; i<amount_lockers; i+=k){ 

在至少如果我正確理解問題。

但是既然你是一個初學者，我認爲它有點改進你的代碼不會有什麼壞處。