php判断月度中最小的日期

php 判断月份中最小的日期
比如：一个数组里边装的日期：2014-01-01,2014-01-02,2014-01-22，2014-02-22,2014-02-26,2014-03-03,2014-03-25,2014-03-28

要达到：把月份中最小的日期取出来，如下所示：

2014-01-01

2014-02-22

2014-03-03

并且计算月份所属日期数：（比如1月份有3个（2014-01-01,2014-01-02,2014-01-22））

01月份-》3

02月份-》2

03月份-》3

这两个功能单独写。请大侠赐教，谢谢！！！！！！！！！


------解决方案--------------------

$ar = array(
  '2014-01-01',
  '2014-01-02',
  '2014-01-22',
  '2014-02-22',
  '2014-02-26',
  '2014-03-03',
  '2014-03-25',
  '2014-03-28',
);
$r1 = $r2 = array();
foreach($ar as $d) {
  list($y, $m, $d) = explode('-', $d);
  if(! isset($r1[$y.$m])) $r1[$y.$m] = 32;
  $r1[$y.$m] = min($r1[$y.$m], $d);
  if(! isset($r2[$y.$m])) $r2[$y.$m] = 0;
  $r2[$y.$m]++;
}
print_r($r1);
print_r($r2);

Array
(
[201401] => 01
[201402] => 22
[201403] => 03
)
Array
(
[201401] => 3
[201402] => 2
[201403] => 3
)

------解决方案--------------------
1.

$arr = array('2014-01-01','2014-01-02','2014-01-22','2014-02-22','2014-02-26','2014-03-03','2014-03-25','2014-03-28');
sort($arr);
$out = array();
foreach ($arr as $key => $value) {
	$mouth = date('n',strtotime($value));
	if(!in_array($mouth, array_keys($out))) $out[$mouth] = $value;
}
var_dump($out);

2.

$arr = array('2014-01-01','2014-01-02','2014-01-22','2014-02-22','2014-02-26','2014-03-03','2014-03-25','2014-03-28');
$newArr = array_map('cout', $arr);
function cout($n){
	return date('n',strtotime($n));
}
print_r ( array_count_values ( $newArr ));

------解决方案--------------------
如果要考虑不同年相同月份的情况，例如2014-02 与 2013-02 需要分开统计。key的值要用Y-m格式。

$months = array('2014-01-01','2014-01-02','2014-01-22','2014-02-22','2014-02-26','2014-03-03','2014-03-25','2014-03-28');

month_min_day($months);

month_days($months);

function month_min_day($months){
    $tmp = array();
    foreach($months as $month){
        $key = date('Y-m',strtotime($month));
        if(!isset($tmp[$key]) 
------解决方案--------------------
 strtotime($month)<$tmp[$key]){
            $tmp[$key] = strtotime($month);
        }
    }
    foreach($tmp as $key=>$val){
        echo date('Y-m-d',$val).'
';
    }
}

function month_days($months){
    $tmp = array();
    foreach($months as $month){
        $key = date('Y-m',strtotime($month));
        isset($tmp[$key])? $tmp[$key]++ : $tmp[$key]=1;
    }
    foreach($tmp as $key=>$val){
        echo $key.'->'.$val.'
';
    }
}
?>