preface

After the first stage of learning, THE information of my learning algorithm was confirmed. This article mainly talks about stack, queue, binary tree and other data structure concept and specific application

Don’t look back, but just push forward!

1. The stack

Linear table, limited operation, first in last out

This topic examines various logical operations of strings, and the author implements them as follows:

function bong(arr) { let ret = [] for(let i of arr) { if(i === 'C') { if(ret.length) { ret.pop() } }else if(i === 'D') {  let pre = ret.slice(-1) ret.push(pre * 2) }else if(i === '+') { let pre1 = ret.slice(-1) let pre2 = ret.slice(-2, -1) ret.push(pre1[0] + pre2[0]) }else { ret.push(i) } } return ret.reduce((acc, num) => (acc + num), 0) }Copy the code