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juliaramosguedes/Longest common prefix

Last active October 1, 2022 15:19
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Algorithms study
Raw
Longest common prefix
const longestCommonPrefix = (strs: string[]): string => {
return strs.reduce((acc, current) => {
while (current.slice(0, acc.length) !== acc) {
acc = acc.slice(0, acc.length - 1);
}
return acc;
}, strs[0])
};
Raw
Merge 2 sorted linked lists
/**
* Definition for singly-linked list.
* class ListNode {
* val: number
* next: ListNode | null
* constructor(val?: number, next?: ListNode | null) {
* this.val = (val===undefined ? 0 : val)
* this.next = (next===undefined ? null : next)
* }
* }
*/
const mergeTwoLists = (list1: ListNode | null, list2: ListNode | null): ListNode | null => {
const head: ListNode = new ListNode();
let curr = head;
while (list1 && list2) {
if (list1.val < list2.val) {
curr.next = list1;
list1 = list1.next;
} else {
curr.next = list2;
list2 = list2.next;
}
curr = curr.next;
}
curr.next = list1 || list2;
return head.next;
};
Raw
Palindrome number
const isPalindrome = (x: number): boolean => {
let num = String(x);
let reversedNum = "";
if (x < 0) {
return false;
}
for (let i = num.length - 1; i >= 0; i--) {
reversedNum += num[i];
if (num.slice(0, reversedNum.length) !== reversedNum) {
return false;
}
}
return true;
};
// without converting into string
const isPalindrome = (x: number): boolean => {
let num = x;
if (num < 0 || (num && num % 10 === 0)) {
return false;
}
const digits = [];
while (num) {
digits.push(num % 10);
num = Math.floor(num / 10);
}
for (let i = 0, j = digits.length - 1; i < j; i++, j--) {
if (digits[i] !== digits[j]) {
return false;
}
}
return true;
};
Raw
Roman to integer
const romanToInt = (s: string): number => {
const romanHash = {
I: 1,
V: 5,
X: 10,
L: 50,
C: 100,
D: 500,
M: 1000,
};
let integer = 0;
for (let i = 0; i < s.length;) {
const currentNumber = romanHash[s[i]];
const nextNumber = romanHash[s[i + 1]];
const isSubtraction = currentNumber < nextNumber;
if (isSubtraction) {
integer += nextNumber - currentNumber;
i += 2;
} else {
integer += currentNumber;
i += 1;
}
}
return integer;
};
Raw
Sort people
const sortPeople = (names: string[], heights: number[]): string[] => {
const sortedNames = [...names];
const sortedHeights = [...heights];
for(let i = 0; i < sortedHeights.length; i++) {
for(let j = i+1; j < sortedHeights.length; j++) {
if(sortedHeights[i] < sortedHeights[j]){
const swapName = sortedNames[i];
sortedNames[i] = sortedNames[j];
sortedNames[j] = swapName;
const swapHeight = sortedHeights[i];
sortedHeights[i] = sortedHeights[j];
sortedHeights[j] = swapHeight;
}
}
}
return sortedNames;
};
Raw
Two Sum
const twoSum = (nums: number[], target: number): number[] => {
for (let i = 0; i < nums.length; i++) {
const firstNumber = nums[i];
if (target >= 0 && firstNumber <= target || target < 0 && firstNumber >= target) {
for (let j = 0; j < nums.length; j++) {
const secondNumber = nums[j]
if (firstNumber + secondNumber === target && i !== j) {
return [i, j]
}
}
}
}
};
Raw
Valid parentheses
const isValid = (s: string): boolean => {
const matchBrackets = {
"(": ")",
"[": "]",
"{": "}",
}
const temp = [];
const openBrackets = Object.keys(matchBrackets);
for (let i = 0; i < s.length; i++) {
const bracket = s[i];
if (openBrackets.includes(bracket)) {
temp.push(bracket);
}
else if (matchBrackets[temp.pop()] !== bracket) {
return false;
}
}
return temp.length === 0;
};
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