Question

pascal补全大括号内的程序：输出1~1000之间的质数，并求出这些质数的和

var n,i,sum:integer;{ };
begin
sum:=2; write(2,' ');
for n:=3 to 999 do
if { } then
begin
flag:=true; i:=2;
while flag and { } do
begin
if { } then flag:=false;
i:=i+1;
end;
if { } then begin write(n,' ');{ };end;
end;
writeln;
writeln('sum=',sum);
end.

Answer 1

var n,i,sum:integer;{flag:boolean};//宣告
begin
sum:=2; write(2,' ');
for n:=3 to 999 do
if { (n mod 2)=1 } then //当n为奇数时，执行
begin
flag:=true; i:=2;
while flag and {i<n} do //循环的条件
begin
if {(n mod i=0)} then flag:=false;//如果n被i除余0那麼n不为质数;
i:=i+1;
end;
if {flag} then begin write(n,' ');{inc(sum,n)};end; //如果n为质数，那麼印出n的值并累加sum;
end;
writeln;
writeln('sum=',sum);
end.

Answer 2

var n,i,sum:integer;{ flag: boolean };
begin
sum:=2; write(2,' ');
for n:=3 to 999 do
if { odd(n) } then
begin
flag:=true; i:=2;
while flag and { i < n } do
begin
if { n mod i = 0 } then flag:=false;
i:=i+1;
end;
if { flag } then begin write(n,' ');{ sum:= sum + n };end;
end;
writeln;
writeln('sum=',sum);
end.

Answer 3

for i:=3 to 1000 do
for j:=2 to i-1