program matrica;
uses crt;
type matr = array[1..25,1..25] of integer;
var
r:matr;
i,j,n:integer;
kol:integer;
sr:real;
procedure sred(mas:matr;m:integer);
var
q,w:integer;
sr:real;
kol:integer;
sum:integer;
begin
sum:=0;
kol:=0;
for q:=1 to m do
begin
for w:=1 to m do
begin
if q=w then
begin
kol:=kol+1;
sum:=sum+mas[q,w];
write(mas[q,w]:4);
end;
sr:=sum/kol;
end;
end;
writeln;
writeln('среднее арифм. равно ',sr:4:2);
end;
begin
clrscr;
randomize;
write('введите порядок матрицы ');readln(n);
for i:=1 to n do
begin
for j:=1 to n do
begin
r[i,j]:=random(101)-50;
write(r[i,j]:4);
end;
writeln;
end;
writeln;
sred(r,n);
readln;
end.