查找：顺序查找、折半查找

// 顺序查找
program SeqSearch;
const Num = 9;
var
        x, i : integer;
        a : array[1 .. Num] of integer;
begin
        readln(x);
        for i := 1 to Num do
                read(a[i]);
        for i := 1 to Num do
                if a[i] = x then
                begin
                        writeln(i);
                        break;
                end;
        if a[i] <> x then
        writeln('Don''t find');
        readln;
        readln;
end.


// 折半查找
program BinSearch;
const Num = 9;
var
        x, i, low, high, mid : integer;
        a : array[1 .. Num] of integer;
begin
        readln(x);
        for i := 1 to Num do
                read(a[i]);
        low := 1;
        high := Num;
        while (low <= high) do
        begin
                mid := (low+high) div 2;
                if x < a[mid] then
                        high := mid-1
                else if x > a[mid] then
                        low := mid+1
                else
                begin
                        writeln(mid);
                        break;
                end;
        end;
        if a[mid] <> x then
                writeln('Don''t find');
        readln;
        readln;
end.