input [1,8,9]
output [[1],[1,8],[1,8,9],[8],[8,9],[9]]
It seems like subset array but i would like to get this output with two pointer way. let's say leftP=0, rightP=0; and then by using for loop, the rightP will increase up to the end of array until there's no more elements and then leftP move by 1...
1 -> [1], [1,8],[1,8,9]
8 -> [8],[8,9]
9 -> [9]
function solution(arr) {
let totalArr = [];
let leftP = 0;
for(let rightP=0; rightP<arr.length; rightP++) {
totalArr.push(arr[rightP]);
// this is where i'm kinda stuck
while()
}
}
You can easily achieve this using just 2 for loop as you are doing as:
i is here leftP and j is here rightP
const arr = [1, 8, 9];
const result = [];
for (let i = 0; i < arr.length; ++i) {
let temp = [arr[i]];
result.push([...temp]);
for (let j = i + 1; j < arr.length; ++j) {
temp.push(arr[j]);
result.push([...temp]);
}
temp = [];
}
console.log(result);/* This is not a part of answer. It is just to give the output full height. So IGNORE IT */
.as-console-wrapper { max-height: 100% !important; top: 0; }Simply slice the array using the two pointers!
Working solution below:
const arr = [1, 8, 9];
const solution = (arr) => {
const resArr = [];
for (let i = 0; i < arr.length; i++) {
for (let j = i + 1; j <= arr.length; j++) {
resArr.push(arr.slice(i, j));
}
}
return resArr;
};
console.log(solution(arr));I would just translate your logic into code, noting that you would need two nested loops.
function solution(arr) {
let totalArr = [];
for (let left = 0; left < arr.length; left++) {
totalArr.push([]);
for (let right = left + 1; right <= arr.length; right++) {
totalArr[left].push(arr.slice(left, right));
}
}
return totalArr;
}
console.log(JSON.stringify(solution([1, 8, 9])));.as-console-wrapper {
max-height: 100% !important;
top: auto;
}(note that this groups them based on left - to make the array flat):
function solution(arr) {
let totalArr = [];
for (let left = 0; left < arr.length; left++) {
for (let right = left + 1; right <= arr.length; right++) {
totalArr.push(arr.slice(left, right));
}
}
return totalArr;
}
console.log(JSON.stringify(solution([1, 8, 9])));.as-console-wrapper {
max-height: 100% !important;
top: auto;
}