#include<iostream>
using namespace std;

void reverse(int arr[],int n){
    int start=0,end=n-1;
    int temp;
    while(start<=end){
        temp=arr[end];
        arr[end]=arr[start];
        arr[start]=temp;
    }
    
    start  ;
    end--;
}

void print(int arr[],int n){
    for(int i=0;i<n;i  ){
        cout<<arr;
    }
    cout<<endl;
}

int main(){
    int arr[5]={1,2,3,4,5};
    int brr[6]={3,6,8,2,1,0};
    reverse(arr,5);
    reverse(brr,6);
    print(arr,5);
    print(brr,6);
}

I am not able to run this code at any compiler, can anyone tell me where I am making the mistake after running it I am getting nothing

CodePudding user response：

I am not to happy about the material that is teaching you C . For one it still uses "C" style arrays, and it is learning you to write using namespace std; which will lead to problems (name clashes) in big projects. So if you have a teacher tell him about this.

Here is a more C oriented example :

#include <algorithm>
#include <iostream>
#include <vector>

// Using namespace std; <-- No unlearn this

// don't use "C" style arrays, use std::array or std::vector
// "C" style arrays are inherently more "buggy" to use.
// for one it easy to get mismatch array size and the size you pass.
void reverse(std::vector<int>& values)
{
    //std::reverse(values.begin(), values.end()); C   has this out of the box for you

    std::size_t left_pos = 0ul;
    std::size_t right_pos = values.size() - 1; // last index in array

    /// manually, you start with first and last element and swap them
    // then move left position one to the right, and right position one to the left
    // repeat until left_pos and right_pos cross.
    for (; left_pos < right_pos;   left_pos, --right_pos)
    {
        // c   has a swap method to swap values 
        std::swap(values[left_pos], values[right_pos]);
    }
}


// prints the content of the vector
std::ostream& operator<<(std::ostream& os, const std::vector<int>& values)
{
    bool print_comma{ false };

    for (const int value : values)
    {
        if (print_comma) std::cout << ",";
        std::cout << value;
        print_comma = true;
    }

    std::cout << "\n";

    return os;
}


int main()
{
    std::vector<int> arr1{ 1,2,3,4,5 };

    reverse(arr1);
    std::cout << arr1;

    return 0;
}

CodePudding user response：

Just for your information: I would recommend you to just use std::reverse() for the concrete example. Also, do not use raw arrays.

#include <algorithm>
#include <iostream>

template <typename T>
void print(const T& arr) {
    for (auto &value: arr) {
        std::cout << value << " ";
    }
    std::cout << "\n";
}

int main(){
    std::array arr={1,2,3,4,5}; // Or just use a std::vector
    std::array brr={3,6,8,2,1,0};
    std::reverse(arr.begin(), arr.end());
    std::reverse(brr.begin(), brr.end());
    print(arr);
    print(brr);
}