Interview questions shared in today's group

 As usual , Click on the learning exchange group before going to bed , Today, there was no fishing in the Group , Discussing interview questions , It immediately brought up my interest , Crouched for a while , I sent three interview questions , I tried it .

1

topic

My solution

let arr = [4, 5, 5, 3, 2, 8, 7];
let arr2 = [60, 90, 80, 110, 120, 90, 100, 90, 100, 100];
const fn = function(arr) {
    
    let min = arr[arr.length - 1];
    let result = [];
    arr.reverse().forEach((item, index) => {
    
        if (item <= min) {
    
            min = item;
            result.push(arr.length - 1 - index);
        }
    });
    return result.reverse();
};

console.log(fn(arr));
console.log(fn(arr2));

2.

topic

My solution

const arr = [1, 2, 3, 4, 1, 2];
const obj2 = {
    
    value: 0,
    child: [],
};
const fn = function(arr, obj) {
    
    if (arr.length >= 2) {
    
        obj.child.push({
     value: arr[0], child: [] });
        obj.child.push({
     value: arr[1], child: [] });
        fn(arr.slice(2, arr.length), obj.child[0]);
        fn(arr.slice(3, arr.length), obj.child[1]);
    } else if (arr.length === 1) {
    
        obj.child.push({
     value: arr[0], child: [] });
        fn(arr.slice(2, arr.length), obj.child[0]);
    }
};
fn(arr, obj2);
console.log(obj2);
const arr2 = [];
const fn2 = function(obj2, sum) {
    
    sum = sum + obj2.value;
    if (obj2.child.length === 1) {
    
        fn2(obj2.child[0], sum);
    } else if (obj2.child.length === 2) {
    
        fn2(obj2.child[0], sum);
        fn2(obj2.child[1], sum);
    } else {
    
        arr2.push(sum);
    }
};

fn2(obj2, 0);
console.log(arr2.sort()[arr2.length - 1]);

3.

topic

My thoughts

 When you give me this question , What I think of is the public longest substring in the query string 
 So as to get the start coordinate or end coordinate of the modified content 
 And then intercept it 0 A string from the start coordinate or the end coordinate to the maximum length of the string 
 Query the public longest substring again 
 In this way, you can get the start and end coordinates of the modified content 
 Then cut this paragraph out to be the content you modified 

Code implementation follow-up