Draw a descendant pyramid (addition)

Question

Challenge

Given a sequence of non-negative integers, create a function that output a descendant pyramid where the children are the sum of both parent numbers.

The result is outputted as an string using tab \t.

Note: trailing tabs on each line are not required

1\t\t2\t\t3\n\t3\t\t5\t\n\t\t8\t\t results in 
1       2       3
    3       5   
        8       

Optionally result can be outputted as an array using an empty position as space.

[[1,,2,,3],
[,3,,5,],
[,,8,,]]

Example:

Given 4,5,7,3,4,2 Output:

4       5       7       3       4       2
    9       12      10      7       6
        21      22      17      13
            43      39      30
                82      69
                    151

Rules

• Standard code-golf rules apply
• Input can be a string using any separator or an array
• Leading/trailing newlines and tabs are permitted (but not required as long as the output is an inverted pyramid)

Test Cases

Input: 1,3,5

1       3       5
    4       8
        12


Input: 9,8,7,6,5

9       8       7       6       5
    17      15      13      11
        32      28      24
            60      52
                112


Input: 5,5,2,5

[[5,,5,,2,,5],
[,10,,7,,7,],
[,,17,,14,,],
[,,,31,,,]]

Input: 3,3,3

[[3,,3,,3],
[,6,,6,],
[,,12,,]]

Winning criteria is code-golf

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Note: This challenge is very close to Generate Pascal's triangle. The difference is the custom starting sequence (pascal goes from 1 and in ascendant mode, this from an input and in descendant mode).

Sandbox post

Answer 1

Jelly,  14  13 bytes

^{14 -> 13 assumes trailing spaces-only entry is allowed in the list format output; if not I shall revert to the 14 (asked)}

+ƝƬK€z⁶Zṙ"JC$

A monadic link. Output is a list of lists using space characters as the spaces (includes a single trailing spaces-only entry).

Try it online! (includes a footer to show the list structure since running the monadic link as a full program will print smashed output implicitly.)

Answer 2

APL (Dyalog Unicode), 31 28 bytes^SBCS

Tacit prefix function. Uses a single space as empty slot marker. Returns list of lists of numbers/spaces.

⍳∘≢{∊(⍺⍴''),,∘' '¨2+/⍣⍺⊢⍵}¨⊂

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⍳∘≢{…}¨⊂ apply the below function for each of
⍳ the ɩndices ∘ of ≢ the tally with
⊂ the entire argument:

 ⊢⍵ yield the right argument (the original input)

 2+/⍣⍺ apply pairwise sum as many times as indicated by the left argument

 ,∘' '¨ append a space to each number

 (…), append that to the following:

  ⍺⍴'' left-argument elements of the empty string (padded with spaces)

 ∊ ϵnlist (flatten)

Answer 3

05AB1E, 15 14 bytes

-1 bytes thanks to Kevin Cruijssen

vD„		ý'	N×ì,ü+

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Answer 4

Wolfram Language (Mathematica), 74 bytes

ArrayPad[Riffle[#,],k++,]&/@NestList[k=0;BlockMap[Tr,#,2,1]&,#,Tr[1^#]-1]&

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Answer 5

Husk, 22 bytes

zoΣ~+R"	"oJ"		"msNU¡Ẋ+

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Explanation

z(Σ~+R" "(J"  "ms))NU¡Ẋ+  -- example input: [1,2,3]
                     ¡    -- infinitely do and collect in list
                      Ẋ+  -- | sum adjacent
                          -- : [[1,2,3],[3,5],[8],[],[],...
                    U     -- keep up until first repetition: [[1,2,3],[3,5],[8],[]]
z(                )N      -- zip with natural numbers under (example on 1 [1,2,3])
   ~+    (       )        -- | join arguments modified by
     R" "                 -- | | replicate tab: " "
               ms         -- | | show each: ["1","2","3"]
          J"  "           -- | | join with 2 tabs: ["1","  ","2","  ","3"]
                          -- | : [" ","1","  ","2","  ","3"]
  Σ                       -- | concatenate: " 1  2  3"
                          -- : [" 1  2  3","  3  5","   8"]

Answer 6

JavaScript (ES6), 73 bytes

Weird source code ... Anyway, that's code-golf!

Includes leading and trailing whitespace.

f=(a,p=`
`)=>p+a.join`		`+(1/(y=a.shift())?f(a.map(x=>y+(y=x)),p+`	`):'')

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Answer 7

Perl 5 -a, 62 bytes

$,="\t\t";do{say"\t"x$i++,@F;map$_+=$F[++$q[@F]],@F}while$#F--

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Answer 8

Python 3, 101 93 80 bytes

Saved 7 bytes (map(str,x) instead of for in and init y as '') and got rid of the trailing newlines (x and[ instead of print(), thanks to Jo King.

Saved 13 bytes ([*map(sum,zip(x,x[1:]))] instead of [x[j]+x[j+1]for j in range(len(x)-1)]) thanks to ovs.

f=lambda x,y='':x and[y+'		'.join(map(str,x))]+f([*map(sum,zip(x,x[1:]))],y+'	')

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Answer 9

Retina, 35 bytes

+¶<`\d+ *(?=(\d+)?)
    $#1*$.(*_$1*)   

Try it online! Explanation:

+

Repeat until the buffer stops changing,

¶<`

Print the contents of the buffer before the substitution, with a trailing newline, and

\d+ *(?=(\d+)?)
    $#1*$.(*_$1*)   

Substitute a single number with a pair of tabs, but a number followed by another number with a tab, the sum, and another tab.

Answer 10

Red, 151 bytes

func[b][m: length? b repeat n m[loop n - 1[prin"^-"]print replace/all
form b" ""^-^-"c: copy[]repeat i -1 + length? b[append c b/(i) + b/(i + 1)]b: c]]

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More readable:

f: func [ b ] [
    m: length? b
    repeat n m [
        loop n - 1 [ prin tab ]
        print replace/all form b " " rejoin [ tab tab ]
        c: copy []
        repeat i (length? b) - 1 [
            append c b/(i) + b/(i + 1)
        ]
        b: c
    ]
]

Answer 11

Perl 6, 50 48 bytes

{$_,{say "	"x$++~.join("		");$_[1..*]Z+@$_}...0}

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Anonymous code block that takes a list of integers and prints the inverted pyramid.

Answer 12

C# (Visual C# Compiler), 163 bytes

b=>{var s="";var c=b.Length;for(int i=0;i<c;i++){for(int z=0;z<i;z++)s+="\t";for(int x=0;x<c-i;x++){s+=b[x]+"\t\t";b[x]=x==c-i-1?0:b[x]+b[x+1];}s+="\n";}return s;}

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Readable:

b =>    {
            var s = "";
            var c = b.Length;
            for (int i = 0; i < c; i++)
            {
                for (int z = 0; z < i; z++)
                    s += "\t";
                for (int x = 0; x < c - i; x++)
                {
                    s += b[x] + "\t\t";
                    b[x] = x == c - i - 1 ? 0 : b[x] + b[x + 1];
                }
                s += "\n";
            }
            return s;
        }

Answer 13

Japt -Rx, 20 18 bytes

The second line includes a trailing tab.

Nc¡=ä+
Ëq' ² iEç'  

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Explanation

                  :Implicit input of array U
N                 :The array of inputs (NOT the input array)
 c                :Concatenate
  ¡               :  Map U
    ä+            :    Consecutive sums of U
   =              :    Reassign to U for next iteration
\n                :Reassign the resulting 2D-array to U
Ë                 :Map each array at index E
 q                :  Join with
  '\t             :   Tab
     ²            :   Repeated twice
       i          :  Prepend
          '\t     :   Tab
         ç        :   Repeated
        E         :   E times
                  :Implicitly join with newlines, trim (not strictly necessary) and output.

Answer 14

C (clang), 112 109 bytes

• -3 from @ceilingcat

j,k;f(*i,c){for(j=c;j;j-=puts("")){for(k=c-j;k--;)putchar(9);for(;++k<j;i[k]+=i[k+1])printf("%d\t\t",i[k]);}}

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Answer 15

Vyxal, 18 bytes

2lṠ)↔ðdvj:ẏ$꘍⁋ð9CV

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I think this works? Output format is annoying.

   )↔              # Repeat until no change, collecting values
  Ṡ                # Sums of
2l                 # Consecutive pairs
       vj          # Join each by...
     ðd            # Double spaces
           $꘍      # Pad left with spaces by
         :ẏ        # range(0, len(list)
             ⁋     # Join by newlines
                 V # Replace
              ð    # Spaces
               9C  # With tabs

Answer 16

Python 3, 79 75 70 bytes

Has leading tabs. Prints the required output then prints trailing tabs and newlines forever.

def f(x,y='\n'):print(y,*x,sep='        ');f([*map(sum,zip(x,x[1:]))],y+'   ')

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Answer 17

Ruby, 67 bytes

A straightforward recursive solution.

F=->a,n=0{puts ?\t*n+a*"		"
a[0]&&F[a.each_cons(2).map(&:sum),n+1]}

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