freecodecamp 初级算法地址戳这里 Reverse a String 翻转字符串 function reverseString(str) { str=str.split("").reverse().join(""); return str; } reverseString("hello") Factorialize a Number 计算一个整数的阶乘 function factorialize(num) { if(num>1){…
Problem Figure 2. The Hamming distance between these two strings is 7. Mismatched symbols are colored red. Given two strings ss and tt of equal length, the Hamming distance between ss and tt, denoted dH(s,t)dH(s,t), is the number of corresponding sym…
freecodecamp 中级算法地址戳这里 Sum All Numbers in a Range 我们会传递给你一个包含两个数字的数组.返回这两个数字和它们之间所有数字的和. function sumAll(arr) { arr.sort(function(a,b){ return a-b; }); var a=arr[0]; var sum=arr[0]; while( a<arr[1] ){ a++; sum+=a; } return sum; } sumAll([1, 4]); Diff…
Managing state is one of the hardest things to do in any application. Angular 2 tackles this problem by making it easy to implement a reactive, uni-directional data flow that favor immutable operations. We are moving in the right direction in Angular…
