IMP:mat_pat

#include <iostream>
using namespace std;

int main()
{
    int a[100][100],n,i,j;
    cout<<"n=";
    cin>>n;
    for (i=0; i<n; i++)
        for (j=0; j<n; j++)
            cin>>a[i][j];
    cout<<"Elemente de sub diagonala pricipala: ";
    for (i=1; i<n; i++)
        for (j=0; j<i; j++)
            cout<<a[i][j]<<' ';
    cout<<endl;
    cout<<"Elemente de pe diagonala principala: ";
    for (i=0; i<n; i++)
        cout<<a[i][i]<<' ';
    cout<<endl;
    cout<<"Elementele de deasupra diagonalei pricipale: ";
    for (i=0; i<n-1; i++)
        for (j=i+1; j<n; j++)
            cout<<a[i][j]<<' ';
    cout<<endl;
    cout<<"MODIFICARE MATRICE:"<<endl;
    cout<<"-cresc cu 1 elementele de sub diagonala principala;"<<endl;
    cout<<"-ridic la patrat elementele de pe diagonala principala;"<<endl;
    cout<<"-scad cu 1 elementele de peste diagonala principala;"<<endl;
    for (i=0; i<n; i++)
        for (j=0; j<n; j++)
            if (j<i)
                a[i][j]++;
            else if (i==j)
                a[i][j]*=a[i][j];
            else if (j>i)
                a[i][j]--;
    cout<<"NOUA MATRICE E:"<<endl;
    for (i=0; i<n; i++)
    {
        for (j=0; j<n; j++)
            cout<<a[i][j]<<' ';
        cout<<endl;
    }

    cout<<"DE ACUM SE FACE REFERINTA LA NOUA MATRICE!"<<endl;
    cout<<"Elementele sub diagonala secundara: "<<endl;
    for (i=1; i<n; i++)
        for (j=n-i; j<n; j++)
            cout<<a[i][j]<<' ';
    cout<<endl;
    cout<<"Elementele de pe diagonala secundara:"<<endl;
    for (i=0; i<n; i++)
        cout<<a[i][n-i-1]<<' ';
    cout<<endl;
    cout<<"Elementele de peste diagonala secundara:"<<endl;
    for (i=0; i<n-1; i++)
        for (j=0; j<n-i-1; j++)
            cout<<a[i][j]<<' ';
    cout<<endl;
    cout<<"MODIFICARE MATRICE:"<<endl;
    cout<<"-cresc cu 1 elementele de sub diagonala secundara;"<<endl;
    cout<<"-ridic la patrat elementele de pe diagonala secundara;"<<endl;
    cout<<"-scad cu 1 elementele de peste diagonala secundara;"<<endl;
    for (i=0; i<n; i++)
        for (j=0; j<n; j++)
            if (j>n-i-1)
                a[i][j]++;
            else if (j==n-i-1)
                a[i][j]*=a[i][j];
            else if (j<n-i-1)
                a[i][j]--;
    cout<<"NOUA MATRICE E:"<<endl;
    for (i=0; i<n; i++)
    {
        for (j=0; j<n; j++)
            cout<<a[i][j]<<' ';
        cout<<endl;
    }
    return 0;
}