\(B_{i,j} = A_{j,i}\) holds, so the matrix \(B\) can be found based on this property.

Double for loop may be difficult at first, so please also refer to the sample code below.

Some programming languages have libraries that find the transpose matrix. Check it out if you are interested in.

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

signed main(){
    ll h,w;cin>>h>>w;
    ll a[h][w];
    for(ll i=0;i<=h-1;i++){
        for(ll j=0;j<=w-1;j++){
            cin>>a[i][j];
        }
    }

    ll b[w][h];
    for(ll i=0;i<=w-1;i++){
        for(ll j=0;j<=h-1;j++){
            b[i][j]=a[j][i];
        }
    }

    for(ll i=0;i<=w-1;i++){
        for(ll j=0;j<=h-1;j++){
            cout<<b[i][j];
            if(j<h-1)cout<<" ";
            else cout<<endl;
        }
    }

    return 0;
}