c_cpp GFG以给定大小的组反转数组

Posted 2021-05-14

#include<iostream>
#include<bits/stdc++.h>
using namespace std;

// #Problem #Arrays #GFG
// https://www.geeksforgeeks.org/reverse-an-array-in-groups-of-given-size/

void rev( vector<int> &a,int l,int r){
    int n=r-l+1;
    for(int i=0;i<n/2;i++){
        int temp=a[l+i];
        a[l+i]=a[r-i];
        a[r-i]=temp;
    }
    /*
        Alternate way to reverse
        while(l<r){
            int temp=a[r];
            a[l]=a[r];
            a[r]=temp;
            l++;
            r--;
        }
    
    */
}

int main(){
    int t;
    cin>>t;
    while(t--){
        int n;
        cin>>n;
        vector<int> a(n);
        for(int i=0;i<n;i++){
            cin>>a[i];
        }
        int k;
        cin>>k;
        int i=0;
        while(i<n){
            int r=i+k-1;
            if(i+k>n-1){
                r=n-1;
            }
            rev(a,i,r);
            i+=k;
        }
        for(int i=0;i<n;i++){
            cout<<a[i]<<" ";
        }
        cout<<endl;
        
    }
    return 0;
}