контролно

#include <iostream>
using namespace std;

int main(){
int arr[10][10];
    int rows = 0;
    int columns = 0;
    int sum = 0;
    cout<<"rows: ";
    cin>>rows;
    cout<<"columns: ";
    cin>>columns;

    while(rows!=columns){
    cout<<"square matrix required. try again"<<endl;

    cout<<"rows: ";
    cin>>rows;
    cout<<"columns: ";
    cin>>columns;
}
    for(int i = 0; i<rows; i++){
        for (int j = 0; j<columns; j++){
        cout<<"arr["<<i<<"]["<<j<<"] = ";
            cin>>arr[i][j];
    }
    }

    for(int i = 0; i<rows; i++){
        for (int j = 0; j<columns; j++){
            if(i<=j){
            sum+=arr[i][j];
        }
            if((i+j)>(columns-1)){
            sum+=arr[i][j];
        }

    }
        }
    cout<<"sum= "<<sum<<endl;
    return 0;
    }