[Algorithm] Reverse array of Chars by word
For example we have:
["p", "r", "e", "f", "e", "t", " ", "m", "a", "k", "e", " ", "p", "r", "a", "t", "i", " c", "e"]
We want to get:
["p", "r", "a", "t", "i", " c", "e", " ", "m", "a", "k", "e", " ", "p", "r", "e", "f", "e", "t"]
Requirement:
You can only do in array swap, you cannot create a new array.
The way to do it:
1. Reverse whole string to get:
["e", " c", "i", "t", "a", "r", "p", " ", "e", "k", "a", "m", " ", "t", "e", "f", "e", "r", "p"]
2. Then we reverse each word to get final result:
["p", "r", "a", "t", "i", " c", "e", " ", "m", "a", "k", "e", " ", "p", "r", "e", "f", "e", "t"]
So the main function should looks like this:
let data = [
"p","r","e","f","e","t"," ",
"m","a","k","e"," ",
"p","r","a","t","i","c","e"
]; function main(_data) {
let data = _data.slice(); reverseWholeString(data);
reverseWords(data, ); return data;
} console.log(main(data));
The reverseWholeString function would be:
function reverseWholeString(data) {
let start = ,
end = data.length - ;
reverseChars(data, start, end);
} function reverseChars(data, start, end) {
while (start < end) {
[data[start], data[end]] = [data[end], data[start]];
start++;
end--;
}
}
reverseWords function would be:
function reverseWords(data, start) {
let index = findEmptyIndex(data, start);
let end = index - ; while (index !== -) {
reverseChars(data, start, end);
start = index + ;
index = findEmptyIndex(data, start);
end = index - ;
} reverseChars(data, start, data.length - );
} function findEmptyIndex(data, start) {
let index;
for (let i = start; i < data.length; i++) {
if (data[i] === " ") {
index = i;
break;
} else {
index = -;
}
} return index;
}
------------
Full code:
let data = [
"p",
"r",
"e",
"f",
"e",
"t",
" ",
"m",
"a",
"k",
"e",
" ",
"p",
"r",
"a",
"t",
"i",
" c",
"e"
]; function reverseWholeString(data) {
let start = 0,
end = data.length - 1;
reverseChars(data, start, end);
} function reverseChars(data, start, end) {
while (start < end) {
[data[start], data[end]] = [data[end], data[start]];
start++;
end--;
}
} function findEmptyIndex(data, start) {
let index;
for (let i = start; i < data.length; i++) {
if (data[i] === " ") {
index = i;
break;
} else {
index = -1;
}
} return index;
}
function reverseWords(data, start) {
let index = findEmptyIndex(data, start);
let end = index - 1; while (index !== -1) {
reverseChars(data, start, end);
start = index + 1;
index = findEmptyIndex(data, start);
end = index - 1;
} reverseChars(data, start, data.length - 1);
} function main(_data) {
let data = _data.slice(); reverseWholeString(data);
reverseWords(data, 0); return data;
} console.log(main(data));
[Algorithm] Reverse array of Chars by word的更多相关文章
- [Algorithm] Reverse a linked list
It helps to understands how recursive calls works. function Node(val) { return { val, next: null }; ...
- [Algorithm] Chunk Array
// --- Directions// Given an array and chunk size, divide the array into many subarrays// where each ...
- Reverse array
数组颠倒算法 #include <iostream> #include <iterator> using namespace std; void reverse(int* A, ...
- reverse array java
/* package whatever; // don't place package name! */ import java.util.*; import java.lang.*; import ...
- CUDA学习,使用shared memory实现Reverse Array
- java.lang.String
1.String 是一个类,广泛应用于 Java 程序中,相当于一系列的字符串.在 Java 语言中 strings are objects.创建一个 strings 最直接的方式是 String g ...
- Java基础教程(20)--数字和字符串
一.数字 在用到数字时,大多数情况下我们都会使用基本数据类型.例如: int i = 500; float gpa = 3.65f; byte mask = 0xff; 然而,有时候我们既需要 ...
- [Swift]LeetCode557. 反转字符串中的单词 III | Reverse Words in a String III
Given a string, you need to reverse the order of characters in each word within a sentence while sti ...
- JavaScript Array 常用函数整理
按字母顺序整理 索引 Array.prototype.concat() Array.prototype.filter() Array.prototype.indexOf() Array.prototy ...
随机推荐
- Python类总结-字段,方法,属性区别及StaticMethod, Property,私有字段和私有属性
类包含下列 静态属性 动态属性 静态方法 动态方法 class Province: #静态字段--属于类,调用方法类.字段名 memo = "中国23个省之一" #动态字段--属于 ...
- 如何正确地使用Java的@deprecated标注
没有什么事情比看到一个没有任何说明的@deprecated标注更让人愤怒的事情了.这种做法只能让人困惑,我到底还要不要用这个已经‘废弃’的方法?如果开发者不希望某个方法再被人用的话,就要好好地为@de ...
- Can you find it? HDU - 2141 (二分查找)
Give you three sequences of numbers A, B, C, then we give you a number X. Now you need to calculate ...
- Number lengths FZU - 1050
N! (N factorial) can be quite irritating and difficult to compute for large values of N. So instead ...
- CodeForces 1063B. Labyrinth 性质
给定$n *m$的格子 询问从$(r, c)$开始最多向左走$x$步,向右走$y$步 询问有多少个格子可以从$(r, c)$到达 有障碍物,$n, m \leqslant 2 * 10^3$ 对于一个 ...
- [BZOJ4521][CQOI2016]手机号码(数位DP)
4521: [Cqoi2016]手机号码 Time Limit: 10 Sec Memory Limit: 512 MBSubmit: 875 Solved: 507[Submit][Status ...
- 【BZOJ】1042: [HAOI2008]硬币购物
1042: [HAOI2008]硬币购物 Time Limit: 10 Sec Memory Limit: 162 MBSubmit: 3307 Solved: 2075[Submit][Stat ...
- PAT甲级1021. Deepest Root
PAT甲级1021. Deepest Root 题意: 连接和非循环的图可以被认为是一棵树.树的高度取决于所选的根.现在你应该找到导致最高树的根.这样的根称为最深根. 输入规格: 每个输入文件包含一个 ...
- JVM堆设置及调优
1.JVM堆设置 -Xmx3550m 设置JVM最大堆内存 为3550M. -Xms3550m 设置JVM初始堆内存 为3550M.此值可以设置与-Xmx相同,以避免每次垃圾回收完成后JVM重新分配内 ...
- css背景图片模糊
index.html <image class="bg" src="/images/bg.png"></image> index.css ...