11.3.1. Флойд - 1.

#include <cstdlib>
#include <iostream>

using namespace std;

int **a;

int main()
{
    int n;
    cin >> n;
    a = new int*[n];
    for (int i = 0; i<n; i++)
    {
        a[i] = new int[n];
        for (int j = 0; j<n; j++)
        {
            cin >> a[i][j];
        }
    }

    for (int k = 0; k<n; k++)
    {
        for (int i = 0; i<n; i++)
        {
            for (int j = 0; j<n; j++)
            {
                if (i != j)
                {
                    a[i][j] = min(a[i][j], a[i][k] + a[k][j]);
                }
            }
        }
    }

    for (int i = 0; i<n; i++)
    {
        for (int j = 0; j<n; j++)
        {
            cout << a[i][j] << (j + 1 == n ? '\n' : ' ');
        }
    }
}