n,m=map(int,input().split())
a=[[0 for i in range(1000)]for i in range(1000)]
for i in range(n):
    a[i]=list(map(int,input().split()))
for i in range(m):
    for j in range(n):
        print(a[j][i],end=" ")
    print()

代码仅供参考 难点在于如何输入与n，m的位置问题

水题

#include<bits/stdc++.h>

using namespace std;

int main()
{

    int n,m;
    cin >>n>>m;
    int a[n+1][m+1];
    int b[m+1][n+1];
    for(int i=1; i<=n; i++){
        for(int j=1; j<=m; j++){
            cin >>a[i][j];
        }
    }
    for(int i=1; i<=n; i++){
        for(int j=1; j<=m; j++){
            b[j][i]=a[i][j];
        }
    }
    for(int i=1; i<=m; i++){
        for(int j=1; j<=n; j++){
            if(j!=n){cout<<b[i][j]<<" ";}
            else{cout<<b[i][j];}
        }
        cout<<endl;
    }

	return 0;
}