Suma vecinilor diagonalei principale

#include <iostream>
using namespace std;

void citire(int a[][100], int& n) {
    cout << "Introdu nr de linii si coloane: ";  cin >> n;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            cout << "a[" << i << "][" << j << "] = ";
            cin >> a[i][j];
        }
    }
}

void suma(int a[][100], int n) {
    int sum = 0;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (i == 0 && j == 0) continue; // next iteration
            else {
                if (i == j) {
                    sum += a[i][j - 1] + a[i - 1][j];

                }
            }
        }
    }
    cout << "Suma vecinilor diagonalei principale este: " << sum << endl;
}

int main() {
    int n, a[100][100], sum;
    citire(a, n);
    suma(a, n);
    return 0;
}