循环遍历两个数组,删除perl中的重叠

Question

我有两组范围,由[start,stop]值表示.一些范围重叠,这意味着一个范围的开始位于另一个范围的[开始,停止]之间.我想制作一组没有这种重叠的新范围,并且不包括范围内的任何新值.

范围看起来像这样:

@starts  @ends
      5    108 
      5    187
     44    187
     44    229 
     44    236 
     64    236 
    104    236
    580    644
    632    770

我期望的输出是这样的:

@starts  @ends
      5    236
    580    770

这是因为前七个范围与5 => 236的间隔重叠,后两个与632 => 770的间隔重叠.

这是我试过的代码:

$fix = 0;
foreach (@ends) {  
    if ($starts[$fix + 1] < $ends[$fix]) {
        splice(@ends, $fix, $fix);
        splice(@starts, $fix + 1, $fix + 1);
    } else {
        $fix += 1;
    }
}

我可以自己打印出这些值,我只需要帮助合并算法.

Answer 1

这会就地编辑数组，当它们重叠时简单地折叠边界。

# Since they're sorted by @starts, accept the 0th interval, start at 1
for (1..$#starts) {
    # extra check on array bounds, since we edit in-place
    last unless $_ < @starts;
    # don't need to collapse if no overlap with previous end
    next unless $starts[$_] <= $ends[$_-1];
    # delete this start and the previous end
    splice(@starts,$_,1);
    splice(@ends,$_-1,1);
    # rerun this loop for the same value of $_ since it was deleted
    redo;
}