Compilare: user.cpp:2:71: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type] std::ifstream f ("royfloyd.in");std::ofstream t ("royfloyd.out");main(){short n,i,j,k;f>>n;short v[n][n];for(i=0;i<n;++i)for(j=0;j<n;++j)f>>v[i][j];if(v[i][k]&&v[k][j]&&(v[i][j]>v[i][k]+v[k][j]||!v[i][j])&&i!=j)v[i][j]=v[i][k]+v[k][j];for(i=0;i<n;++i){for(j=0;j<n;++j)t<<v[i][j]<<" ";t<<'\n';}} ^ user.cpp: In function ‘int main()’: user.cpp:2:158: warning: ‘k’ is used uninitialized in this function [-Wuninitialized] std::ifstream f ("royfloyd.in");std::ofstream t ("royfloyd.out");main(){short n,i,j,k;f>>n;short v[n][n];for(i=0;i<n;++i)for(j=0;j<n;++j)f>>v[i][j];if(v[i][k]&&v[k][j]&&(v[i][j]>v[i][k]+v[k][j]||!v[i][j])&&i!=j)v[i][j]=v[i][k]+v[k][j];for(i=0;i<n;++i){for(j=0;j<n;++j)t<<v[i][j]<<" ";t<<'\n';}} ^ user.cpp:2:205: warning: ‘j’ may be used uninitialized in this function [-Wmaybe-uninitialized] std::ifstream f ("royfloyd.in");std::ofstream t ("royfloyd.out");main(){short n,i,j,k;f>>n;short v[n][n];for(i=0;i<n;++i)for(j=0;j<n;++j)f>>v[i][j];if(v[i][k]&&v[k][j]&&(v[i][j]>v[i][k]+v[k][j]||!v[i][j])&&i!=j)v[i][j]=v[i][k]+v[k][j];for(i=0;i<n;++i){for(j=0;j<n;++j)t<<v[i][j]<<" ";t<<'\n';}} ^