# Building a Pyramid

`var prystring = function(char, num){    let string = '\n'    for (let i = 1 ; i <= num; i++){      for(let j = num; j > i; j--){        string += " "                }      for(let k = 0; k < i * 2 -1; k++){        string += `\${char}`      }      for(let j = num; j > i; j--){        string += " "      }      string += "\n"    }  console.log(string)}  prystring('*',5)'    *       ***     *****   ******* *********'var strings = function(char, num){    let string = '\n'    for (let i = 0 ; i < num; i++){      for(let j = 0; j < i; j++){        string += " "                }      for(let k = 0; k < 2 * (num-i) -1; k++){        string += `\${char}`      }      string += "\n"    }  console.log(string)}  strings('*',5)'********* *******  *****   ***    *'`

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# Simple String Sort Function

/*
Simple String Sort Function
Given two arguments, a string of characters (input) and a sort string (sortStr),
implement a simple sort function that returns the characters to sort in the order
specified by the sort string. If any characters do not appear in the sort string,
they go at…

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# Maximum Subarray

Given an integer array `nums`, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum.

Example 1:

`Input: nums = [-2,1,-3,4,-1,2,1,-5,4]Output: 6Explanation: [4,-1,2,1] has the largest sum = 6.`

Example 2:

`Input: nums = [1]Output: 1`

Example 3:

`Input: nums = [5,4,-1,7,8]Output: 23`

Solution:

`var maxSubArray = function(nums) {    let sum = 0;    let maxSum = -Infinity;        if(nums.length === 0) return 0;    if(nums.length === 1) return nums[0]        for(let i = 0;i<nums.length;i++){        sum+=nums[i];        maxSum = Math.max(maxSum,sum);        if(sum < 0) sum = 0;    }    return maxSum;};`

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# intersection

Write a function, intersection, that takes in two arrays, a,b, as arguments. The function should return a new array containing elements that are in both of the two arrays.

You may assume that each input array does not contain duplicate elements.

const intersection = (a, b) => {
// todo
let set = new Set()
let arr = []
for( let i = 0; i < a.length; i++){