Whats wrong in the code

#1

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

void reverse(int *a,int i,int j){
if(i>j){
return;
}
swap(a[i],a[j]);
return reverse(a,i+1,j-1);
}

int main() {
int n;
cin>>n;
int a[n];
for(int i=0;i<n;i++){
cin>>a[i];
}
reverse(a,0,n-1);
for(int i=0;i<n;i++){
cout<<a[i]<<" ";
}

return 0;

}

#2

hi @dhruvj797
Inverse is Simply swapping the value of the array with the value at that index.

Algo

  1. Create a new Array say narr and original array is arr.
  2. now at the arr[i]th index of narr save the ith value.(previously i is the index and arr[i] is the value bt now arr[i] is the index and i is the value.)
  3. return new array.

refer this code -->

#include<iostream>
#include<bits/stdc++.h>
using namespace std;
int main() {
	int N;
	cin>>N;
	int a[N];
	for(int i =0;i<N;i++)
		cin>>a[i];
	int b[N];
	for(int j=0;j<N;j++){
		b[a[j]]=j;
	}
    for(int i=0;i<N;i++){
        cout<<b[i]<<" ";
    }
	return 0;
}
#3

hi @dhruvj797
I hope it’s clear now???

#4

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