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Oct 9, 2023Helper
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return array head

Nov 19, 2022CodeCatch

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const head = arr => (arr && arr.length ? arr[0] : undefined);
head([1, 2, 3]); // 1
head([]); // undefined
head(null); // undefined
head(undefined); // undefined

levenshtein distance

Nov 19, 2022CodeCatch

0 likes • 1 view

const levenshteinDistance = (s, t) => {
if (!s.length) return t.length;
if (!t.length) return s.length;
const arr = [];
for (let i = 0; i <= t.length; i++) {
arr[i] = [i];
for (let j = 1; j <= s.length; j++) {
arr[i][j] =
i === 0
? j
: Math.min(
arr[i - 1][j] + 1,
arr[i][j - 1] + 1,
arr[i - 1][j - 1] + (s[j - 1] === t[i - 1] ? 0 : 1)
);
}
}
return arr[t.length][s.length];
};
levenshteinDistance('duck', 'dark'); // 2

Temperature Converter

Nov 19, 2022CodeCatch

0 likes • 2 views

const celsiusToFahrenheit = (celsius) => celsius * 9/5 + 32;
const fahrenheitToCelsius = (fahrenheit) => (fahrenheit - 32) * 5/9;
// Examples
celsiusToFahrenheit(15); // 59
celsiusToFahrenheit(0); // 32
celsiusToFahrenheit(-20); // -4
fahrenheitToCelsius(59); // 15
fahrenheitToCelsius(32); // 0

Get union of arrays

Nov 19, 2022CodeCatch

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const union = (...arr) => [...new Set(arr.flat())];
// Example
union([1, 2], [2, 3], [3]); // [1, 2, 3]

Redux Slice

Mar 11, 2021C S

1 like • 4 views

import { createSlice } from "@reduxjs/toolkit";
const alert = createSlice({
name: "alert",
initialState: {
msg: "",
status: "",
},
reducers: {
set_alert: (state, action) => {
return {
...state,
msg: action.payload.msg,
status: action.payload.status,
};
},
clear_alert: (state, action) => {
return {
...state,
msg: "",
status: "",
};
},
},
});
export default alert.reducer;
const { set_alert, clear_alert } = alert.actions;
export const setAlert = (msg, status) => dispatch => {
dispatch(set_alert({ msg, status }));
setTimeout(() => dispatch(clear_alert()), 4000);
};
export const clearAlert = () => dispatch => {
dispatch(clear_alert());
};

Tree Traversal

Oct 16, 2023C S

0 likes • 8 views

class TreeNode {
constructor(data, depth) {
this.data = data;
this.children = [];
this.depth = depth;
}
}
function buildNaryTree(hosts) {
const nodeMap = {};
// Step 1: Create a map of nodes using fqdn as the key
hosts.forEach((host) => {
nodeMap[host.fqdn] = new TreeNode(host, 0); // Initialize depth to 0
});
// Step 2: Iterate through the array and add each node to its parent's list of children
hosts.forEach((host) => {
if (host.displayParent) {
if (nodeMap[host.displayParent]) {
const parent = nodeMap[host.displayParent];
const node = nodeMap[host.fqdn];
node.depth = parent.depth + 1; // Update the depth
parent.children.push(node);
} else {
console.error(`Parent with fqdn ${host.displayParent} not found for ${host.fqdn}`);
}
}
});
// Find the root nodes (nodes with no parent)
const rootNodes = hosts.filter((host) => !host.displayParent).map((host) => nodeMap[host.fqdn]);
return rootNodes;
}
function treeToObjects(node) {
const result = [];
function inOrder(node) {
if (!node) {
return;
}
// Visit the current node and add it to the result
result.push(node.data);
// Visit children nodes first
node.children.forEach((child) => {
inOrder(child);
});
}
inOrder(node);
return result;
}
// Usage example
const hosts = [
{
fqdn: 'fqdn_1',
display_name: 'Host 1',
},
{
fqdn: 'fqdn_2',
display_name: 'Host 2',
displayParent: 'fqdn_1',
},
{
fqdn: 'fqdn_3',
display_name: 'Host 3'
},
{
fqdn: 'fqdn_4',
display_name: 'Host 4',
displayParent: 'fqdn_3',
},
{
fqdn: 'fqdn_5',
display_name: 'Host 5',
displayParent: 'fqdn_1',
},
];
const tree = buildNaryTree(hosts);
// Function to convert the tree to an array of objects
function convertTreeToArray(nodes) {
const result = [];
nodes.forEach((node) => {
result.push(...treeToObjects(node));
});
return result;
}
// Convert the tree back to an array of objects
const arrayFromTree = convertTreeToArray(tree);
console.log(arrayFromTree);