uses crt;
var s,ss,ps:string;
k,i,dl:integer;
begin
clrscr;
ps:='abc';
s:='sadf ogjag abc nausdyg abc saiodjfabc ij';
dl:=length(s);
i:=1;
k:=0;
ss:=s;
repeat
k:=k+1;
ss:=copy(ss,i,dl);
i:=pos(ps,ss)+3;
dl:=length(ss)-i;
until(pos(ps,ss)=0);
writeln(k-1);
readln;
end.
Вариант 2
program blablabla;
uses crt;
var
s:string;
i,n:integer;
begin
n:=0;
writeln('vvedite stroky v kotoroj iscem "abc" ');
readln(s);
for i:=1 to length(s)-2 do begin
if (s[i]='a') and (s[i+1]='b') and (s[i+2]='c') then begin
n:=n+1;
end;
end;
if n>0 then
writeln('v fraze "abc" vstrechaetsa ',n,' raz')
else writeln('v fraze "abc" ne vstrechaetsa');
readln;
end.