Recursive algorithm for building nested arrays
I am struggling to generalize this to any depth (example below with depth 4):
var listA = [1,2,3,4,5,6,7,8,9,10,11,12];
var listB = ["A", "B", "C", "D", "E"];
var listC = ["a", "b", "c", "d", "e"];
var listD = ["one"];
var result = [];
for (var listAi = 0; listAi < listA.length; listAi++) {
var a = [];
result.push(a);
for (var listBi = 0; listBi < listB.length; listBi++) {
var b = [];
a.push(b);
for (var listCi = 0; listCi < listC.length; listCi++) {
var c = [];
b.push(c);
for (var listDi = 0; listDi < listD.length; listDi++) {
c.push(listA[listAi] + " " + listB[listBi] + " " + listC[listCi] + " " + listD[listDi]);
}
}
}
}
where is the correct result
[
[
[
["1 A a one"],
["1 A b one"],
["1 A c one"],
["1 A d one"],
["1 A e one"]
],
[
["1 B a one"],
["1 B b one"],
["1 B c one"],
["1 B d one"],
["1 B e one"]
],
[
["1 C a one"],
["1 C b one"],
["1 C c one"],
["1 C d one"],
["1 C e one"]
],
[
["1 D a one"],
["1 D b one"],
["1 D c one"],
["1 D d one"],
["1 D e one"]
],
[
["1 E a one"],
["1 E b one"],
["1 E c one"],
["1 E d one"],
["1 E e one"]
]
],
[
[
["2 A a one"],
["2 A b one"],
["2 A c one"],
["2 A d one"],
["2 A e one"]
],
[
["2 B a one"],
["2 B b one"],
["2 B c one"],
["2 B d one"],
["2 B e one"]
],
[
["2 C a one"],
["2 C b one"],
["2 C c one"],
["2 C d one"],
["2 C e one"]
],
[
["2 D a one"],
["2 D b one"],
["2 D c one"],
["2 D d one"],
["2 D e one"]
],
[
["2 E a one"],
["2 E b one"],
["2 E c one"],
["2 E d one"],
["2 E e one"]
]
],
[
[
["3 A a one"],
["3 A b one"],
["3 A c one"],
["3 A d one"],
["3 A e one"]
],
[
["3 B a one"],
["3 B b one"],
["3 B c one"],
["3 B d one"],
["3 B e one"]
],
[
["3 C a one"],
["3 C b one"],
["3 C c one"],
["3 C d one"],
["3 C e one"]
],
[
["3 D a one"],
["3 D b one"],
["3 D c one"],
["3 D d one"],
["3 D e one"]
],
[
["3 E a one"],
["3 E b one"],
["3 E c one"],
["3 E d one"],
["3 E e one"]
]
],
[
[
["4 A a one"],
["4 A b one"],
["4 A c one"],
["4 A d one"],
["4 A e one"]
],
[
["4 B a one"],
["4 B b one"],
["4 B c one"],
["4 B d one"],
["4 B e one"]
],
[
["4 C a one"],
["4 C b one"],
["4 C c one"],
["4 C d one"],
["4 C e one"]
],
[
["4 D a one"],
["4 D b one"],
["4 D c one"],
["4 D d one"],
["4 D e one"]
],
[
["4 E a one"],
["4 E b one"],
["4 E c one"],
["4 E d one"],
["4 E e one"]
]
],
[
[
["5 A a one"],
["5 A b one"],
["5 A c one"],
["5 A d one"],
["5 A e one"]
],
[
["5 B a one"],
["5 B b one"],
["5 B c one"],
["5 B d one"],
["5 B e one"]
],
[
["5 C a one"],
["5 C b one"],
["5 C c one"],
["5 C d one"],
["5 C e one"]
],
[
["5 D a one"],
["5 D b one"],
["5 D c one"],
["5 D d one"],
["5 D e one"]
],
[
["5 E a one"],
["5 E b one"],
["5 E c one"],
["5 E d one"],
["5 E e one"]
]
],
[
[
["6 A a one"],
["6 A b one"],
["6 A c one"],
["6 A d one"],
["6 A e one"]
],
[
["6 B a one"],
["6 B b one"],
["6 B c one"],
["6 B d one"],
["6 B e one"]
],
[
["6 C a one"],
["6 C b one"],
["6 C c one"],
["6 C d one"],
["6 C e one"]
],
[
["6 D a one"],
["6 D b one"],
["6 D c one"],
["6 D d one"],
["6 D e one"]
],
[
["6 E a one"],
["6 E b one"],
["6 E c one"],
["6 E d one"],
["6 E e one"]
]
],
[
[
["7 A a one"],
["7 A b one"],
["7 A c one"],
["7 A d one"],
["7 A e one"]
],
[
["7 B a one"],
["7 B b one"],
["7 B c one"],
["7 B d one"],
["7 B e one"]
],
[
["7 C a one"],
["7 C b one"],
["7 C c one"],
["7 C d one"],
["7 C e one"]
],
[
["7 D a one"],
["7 D b one"],
["7 D c one"],
["7 D d one"],
["7 D e one"]
],
[
["7 E a one"],
["7 E b one"],
["7 E c one"],
["7 E d one"],
["7 E e one"]
]
],
[
[
["8 A a one"],
["8 A b one"],
["8 A c one"],
["8 A d one"],
["8 A e one"]
],
[
["8 B a one"],
["8 B b one"],
["8 B c one"],
["8 B d one"],
["8 B e one"]
],
[
["8 C a one"],
["8 C b one"],
["8 C c one"],
["8 C d one"],
["8 C e one"]
],
[
["8 D a one"],
["8 D b one"],
["8 D c one"],
["8 D d one"],
["8 D e one"]
],
[
["8 E a one"],
["8 E b one"],
["8 E c one"],
["8 E d one"],
["8 E e one"]
]
],
[
[
["9 A a one"],
["9 A b one"],
["9 A c one"],
["9 A d one"],
["9 A e one"]
],
[
["9 B a one"],
["9 B b one"],
["9 B c one"],
["9 B d one"],
["9 B e one"]
],
[
["9 C a one"],
["9 C b one"],
["9 C c one"],
["9 C d one"],
["9 C e one"]
],
[
["9 D a one"],
["9 D b one"],
["9 D c one"],
["9 D d one"],
["9 D e one"]
],
[
["9 E a one"],
["9 E b one"],
["9 E c one"],
["9 E d one"],
["9 E e one"]
]
],
[
[
["10 A a one"],
["10 A b one"],
["10 A c one"],
["10 A d one"],
["10 A e one"]
],
[
["10 B a one"],
["10 B b one"],
["10 B c one"],
["10 B d one"],
["10 B e one"]
],
[
["10 C a one"],
["10 C b one"],
["10 C c one"],
["10 C d one"],
["10 C e one"]
],
[
["10 D a one"],
["10 D b one"],
["10 D c one"],
["10 D d one"],
["10 D e one"]
],
[
["10 E a one"],
["10 E b one"],
["10 E c one"],
["10 E d one"],
["10 E e one"]
]
],
[
[
["11 A a one"],
["11 A b one"],
["11 A c one"],
["11 A d one"],
["11 A e one"]
],
[
["11 B a one"],
["11 B b one"],
["11 B c one"],
["11 B d one"],
["11 B e one"]
],
[
["11 C a one"],
["11 C b one"],
["11 C c one"],
["11 C d one"],
["11 C e one"]
],
[
["11 D a one"],
["11 D b one"],
["11 D c one"],
["11 D d one"],
["11 D e one"]
],
[
["11 E a one"],
["11 E b one"],
["11 E c one"],
["11 E d one"],
["11 E e one"]
]
],
[
[
["12 A a one"],
["12 A b one"],
["12 A c one"],
["12 A d one"],
["12 A e one"]
],
[
["12 B a one"],
["12 B b one"],
["12 B c one"],
["12 B d one"],
["12 B e one"]
],
[
["12 C a one"],
["12 C b one"],
["12 C c one"],
["12 C d one"],
["12 C e one"]
],
[
["12 D a one"],
["12 D b one"],
["12 D c one"],
["12 D d one"],
["12 D e one"]
],
[
["12 E a one"],
["12 E b one"],
["12 E c one"],
["12 E d one"],
["12 E e one"]
]
]
]
I have something like this so far:
var result = [];
function layout(dimensions, curDepth, stack) {
if (curDepth === -1) {
return result.push(stack.slice(0));
}
// for all but the first bout of recursion, this is wrong.
// don't want to be pushing every element onto the stack.
for (var i = 0; i < dimensions[curDepth].length; i++) {
if (curDepth === 3) stack = []; // temporarily hardcoded to 3
stack.push(dimensions[curDepth][i]);
layout(dimensions, curDepth - 1, stack);
}
}
layout([listD, listC, listB, listA], 3);
// [[1,"A","a","one"],[1,"A","a","one","b","one"],[1,"A","a","one","b","one","c","one"] ...
which is wrong (and it assigns the argument).
+3
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2 answers
I liked this question. Here is the fiddle: https://jsfiddle.net/gcbo2aok/1/ (you will need to browse the console to see if the results match your desired output)
var listA = [1,2,3,4,5,6,7,8,9,10,11,12];
var listB = ["A", "B", "C", "D", "E"];
var listC = ["a", "b", "c", "d", "e"];
var listD = ["one"];
function layout(dimentions, depth, position, val){
if(typeof depth === "undefined") depth = -1;
if(typeof val === "undefined") val = "";
else val += " " + dimentions[depth][position];
var retval = [];
if(depth+1<dimentions.length){
for(var i = 0; i < dimentions[depth+1].length; i++){
retval.push(layout(dimentions, depth+1, i, val));
}
}else{
return val;
}
return retval;
};
retval = layout([listA, listB, listC, listD]);
console.log(retval);
+1
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You may try
function process(arrays, stack) {
stack = stack || [];
var array = [],
value = arrays[0];
if (arrays.length == 1) {
for (var i = 0; i < value.length; i++) {
array.push(stack.concat(value[i]).join(' '))
}
} else if (arrays.length) {
for (var i = 0; i < value.length; i++) {
array.push(process(arrays.slice(1), stack.concat(value[i])))
}
}
return array;
}
function process(arrays, stack) {
stack = stack || [];
var array = [],
value = arrays[0];
if (arrays.length == 1) {
for (var i = 0; i < value.length; i++) {
array.push(stack.concat(value[i]).join(' '))
}
} else if (arrays.length) {
for (var i = 0; i < value.length; i++) {
array.push(process(arrays.slice(1), stack.concat(value[i])))
}
}
return array;
}
function test() {
var listA = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12];
var listB = ["A", "B", "C", "D", "E"];
var listC = ["a", "b", "c", "d", "e"];
var listD = ["one", 'two'];
var result = process([listA, listB, listC, listD])
console.log(JSON.stringify(result));
output.innerHTML = JSON.stringify(result)
}
<button onclick="test()">Test</button>
<div id="output"></div>
+1
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