如何在perl中获取数组中最大重复值的所有索引

发布于 2024-12-15 08:22:28 字数 586 浏览 0 评论 0原文

大家好，我是 Perl 新手，正在学习过程中。我有一个数组，

 @array = ( 10, 40, 59, 40, 90, 100, 30, 40, 100, 20, );

我想找到数组中的最大数字，并且还想知道数组中存在最大数字的索引。

我正在做的

my $maxValue = max @array;
print $maxValue;      # displays the maximum number in the entire array

my ($index) = grep $array[$_] eq $maxValue , 0.. $#array;
print ($index);        # this gives me the index of the maximum number which was found in the array.

输出是索引为 5 的 100

但实际上 100 在数组中出现了 2 次：一次在索引 6 处，另一次在索引 8 处。我的代码只向我提供它找到的具有最大值的第一个索引。

如何获得所有具有最大值的索引？

原文

Hi I am new to Perl an in a learning process.
I am having an array

 @array = ( 10, 40, 59, 40, 90, 100, 30, 40, 100, 20, );

I want to find the maximum number in the array and also want to know the index where the maximum number is present in my array.

I am doing

my $maxValue = max @array;
print $maxValue;      # displays the maximum number in the entire array

my ($index) = grep $array[$_] eq $maxValue , 0.. $#array;
print ($index);        # this gives me the index of the maximum number which was found in the array.

The output I am getting is 100 with index 5

But actually 100 is coming 2 times in the array: once at index 6 and again at index 8. My code only provide me the first index it finds with the max value.

How can I get all the index which has maximum value with them?

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怪我太投入 2024-12-22 08:22:28

my @index = grep $array[$_] eq $maxValue , 0.. $#array;
print @index;

似乎是最简单的方法。

尽管对于数字，您确实应该使用 ==，即使例如 100 也是一个有效的字符串。

my @index = grep $array[$_] eq $maxValue , 0.. $#array;
print @index;

Seems to be the simplest way.

Although for numbers, you really should use ==, even though e.g. 100 is also a valid string.

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二货你真萌 2024-12-22 08:22:28

这是一次通过数组来确定最大值和所有索引：

    use warnings;
    use strict;
    use Data::Dumper;

    my @array = ( 10, 40, 59, 40, 90, 100, 30, 40, 100, 20, );
    my %uniq;
    my $i = 0;
    my $max = 0;
    for (@array) {
        push @{ $uniq{$_} }, $i;
        $i++;
        $max = $_ if $_ > $max;
    }
    print "max=$max at indexes:\n";
    print Dumper($uniq{$max});

    __END__

    max=100 at indexes:
    $VAR1 = [
              5,
              8
            ];

另一种方法...没有哈希：

use warnings;
use strict;
use Data::Dumper;

my @array = ( 10, 40, 59, 40, 90, 100, 30, 40, 100, 20, );
my @maxs;
my $i = 0;
my $max = 0;
for (@array) {
    if ($_ > $max) {
        @maxs = $i;
        $max  = $_ ;
    }
    elsif ($_ == $max) {
        push @maxs, $i;
    }
    $i++;
}
print "max=$max at indexes:\n";
print Dumper(\@maxs);

This is one time through the array to determine the max value and all the indexes:

    use warnings;
    use strict;
    use Data::Dumper;

    my @array = ( 10, 40, 59, 40, 90, 100, 30, 40, 100, 20, );
    my %uniq;
    my $i = 0;
    my $max = 0;
    for (@array) {
        push @{ $uniq{$_} }, $i;
        $i++;
        $max = $_ if $_ > $max;
    }
    print "max=$max at indexes:\n";
    print Dumper($uniq{$max});

    __END__

    max=100 at indexes:
    $VAR1 = [
              5,
              8
            ];

Another way... without the hash:

use warnings;
use strict;
use Data::Dumper;

my @array = ( 10, 40, 59, 40, 90, 100, 30, 40, 100, 20, );
my @maxs;
my $i = 0;
my $max = 0;
for (@array) {
    if ($_ > $max) {
        @maxs = $i;
        $max  = $_ ;
    }
    elsif ($_ == $max) {
        push @maxs, $i;
    }
    $i++;
}
print "max=$max at indexes:\n";
print Dumper(\@maxs);

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