Php permutation and combination of numbers 1 to 9 are all equal to 20

<? Php
Set_time_limit (0 );
/*
Function Description: huoqu_zhuhe ($ total, $ num_array, $ isone = 0)
Parameter description: $ total --- sum of several numbers;
$ Num_array ------- addend array: $ num_array = array (1, 2, 3, 4, 5, 6, 7, 8, 9), The addend that can be used;
$ Count: The sum of several numbers. It is not limited to zero.
$ Isone --- whether to use different numbers each time. The value 1 is 0. The default value is 1.

Return type: array. The number is a +-connected string: [0] => 3 + 8 + 9 [1] => 4 + 7 + 9

Test result: 1: the speed of the addend array is relatively small. If it is too large, it is slow; 2: each time you can use a different addend, the processing will be slow.
The following method is used: generate all possible sorting, filter duplicate sorting, and obtain a combination.
*/
Function huoqu_zhuhe ($ total, $ num_array, $ count = 0, $ isone = 1 ){
If (empty ($ num_array) |! Is_array ($ num_array )){
Echo 'error: an array of numbers required '; return false;
}
$ Feishu = 0;
For ($ I = 0; $ I <count ($ num_array); $ I ++ ){
If (! Is_numeric ($ num_array [$ I]) {
$ Feishu = 1;
Break;
}
}

If ($ Feishu = 1 ){
Echo 'error; the array must be a valid number '; return false;
}
$ Lian = $ num_array;
$ Savearr = array ();
While (! Empty ($ Lian )){
// Echo 1;
$ Newarr = array ();
$ K = 0;
For ($ I = 0; $ I <count ($ Lian); $ I ++ ){
$ Lianstr = $ Lian [$ I];
$ Arr = explode ('+', $ lianstr );

$ Nowhe = array_sum ($ ARR );
For ($ J = 0; $ j <count ($ num_array); $ J ++ ){
$ Savestr = $ lianstr. '+'. $ num_array [$ j];
If ($ isone = 1 & in_array ($ num_array [$ j], $ arr ))
Continue;
If ($ nowhe + $ num_array [$ j])> $ total)
Break;
Else if ($ nowhe + $ num_array [$ j]) ==$ total ){
$ Savearr [] = $ savestr;
} Else {
$ Newarr [$ k] = $ savestr; $ k ++;
}
} // End for ($ j = 0; $ j <count ($ num_array)
} // End for ($ I = 0; $ I
$ Lian = $ newarr;
} // End while (! Empty ($ lian ))

If ($ count! = 0 ){
Foreach ($ savearr as $ key => $ number ){
$ Savearr_count = count (explode ('+', $ number ));
If ($ count! = $ Savearr_count)
Unset ($ savearr [$ key]);
}
}

// Generate the combination part and filter duplicates. The two arrays take one as a reference to see if the other can match by moving.

$ Isguolu = array (); // select 0 for storing the corresponding id to get 1
For ($ I = 0; $ I <count ($ savearr); $ I ++ ){
$ Isguolu [] = 0;
} // Initialize all 0

For ($ I = 0; $ I <count ($ savearr); $ I ++ ){
$ Arr1 = explode ('+', $ savearr [$ I]);
$ Len1 = count ($ arr1 );
For ($ j = $ I + 1; $ j <count ($ savearr); $ j ++ ){
$ Arr2 = explode ('+', $ savearr [$ j]);
$ Len2 = count ($ arr2 );
If ($ len1! = $ Len2)
Continue;
If ($ isguolu [$ j] = 1)
Continue;
// Compare $ arr1 and $ arr2
$ Jishu = 0;
For ($ i1 = 0; $ i1 <count ($ arr1); $ i1 ++ ){
$ A = $ arr1 [$ i1];
$ Isyou = 0;

For ($ i2 = $ i1; $ i2 <count ($ arr2); $ i2 ++ ){
If ($ a = $ arr2 [$ i2]) {
$ Jishu ++;
$ Isyou = 1;
$ T = $ arr2 [$ i1];
$ Arr2 [$ i1] = $ arr2 [$ i2];
$ Arr2 [$ I2] = $ t;
Break;
}
} // End for ($ i2 = 0

If ($ isyou = 0) break;

} // End for ($ i1 = 0; $ i1 <count ($ arr1 );

If ($ jishu = $ len1) $ isguolu [$ j] = 1;

} // End for ($ j = $ I + 1;

} // End for ($ I = 0; $ I <count ($ savearr); $ I ++)
// Print_r ($ isguolu );

// Select based on the filter array
$ Newarr = array ();
For ($ I = 0; $ I <count ($ savearr); $ I ++ ){
If ($ isguolu [$ I] = 0) $ newarr [] = $ savearr [$ I];
}
// Print_r ($ newarr );
Return $ newarr;
}

// The following is a test
// Use 1, 2, 3, 4, 5, 6, 7, 8, 9 to add all the combinations equal to 20.
$ Num_array = array (1, 2, 3, 4, 5, 6, 7, 8, 9, 10 );
If ($ jieguo = huoqu_zhuhe (20, $ num_array, 4 )){
Echo '<PRE> ';
Print_r ($ jieguo );
}
 

?>