hunt.txt

来自「delphi数值算法集光盘源代码,用于delphi7科学出版社出版.」· 文本 代码 · 共 47 行

procedure HUNT(XX:array of real; N:integer; X:real; var JLO:integer);
label 1,2,3;
var
    ASCND:boolean; LHI,INC,JM:integer;
begin
    ASCND:=XX[N] > XX[1];
    If (JLO <= 0) Or (JLO > N) Then
    begin
        JLO:=0;
        LHI:=N + 1;
        GoTo 3;
    end;
    INC:=1;
    If (X >= XX[JLO]) = ASCND Then
    begin
1:      LHI:=JLO + INC;
        If LHI > N Then
            LHI:=N + 1
        Else If ((X >= XX[LHI]) = ASCND) Then
        begin
            JLO:=LHI;
            INC:=INC + INC;
            GoTo 1;
        end;
    end
    Else
    begin
        LHI:=JLO;
2:      JLO:=LHI - INC;
        If JLO < 1 Then
            JLO:=0
        Else If (X < XX[JLO]) = ASCND Then
        begin
            LHI:=JLO;
            INC:=INC + INC;
            GoTo 2;
        end;
    end;
3:  If LHI - JLO = 1 Then
        Exit;
    JM:=(LHI + JLO) div 2;
    If (X > XX[JM]) = ASCND Then
        JLO:=JM
    Else
        LHI:=JM;
    GoTo 3;
end;