C++将行和列互换

#include <iostream>
using namespace std;

int main(){
	int n,m,a[100][100],b[100][100];
	cin >> n >> m;
	for (int i = 0;i < n;i ++){
		for (int j = 0;j < m; j ++){
			cin >> a[i][j];
		}
	}
	for (int i = 0;i < n;i ++){
		for (int j = 0;j < m;j ++){
			b[j][i] = a[i][j];
		}
	}
	for (int i = 0;i < m;i ++){
		for (int j = 0;j < n;j ++){
			cout << b[i][j] << " ";
		}
		cout << endl;
	}
	return 0;
}