1、字符串最后一个单词的长度
因为题目要求是获取最后一个单词，所以顺着字符串从后往前查找第一个空格，查找到了第一个空格就知道了当前的长度了
const lineString = readline();
function getLastWordLenghth(str){
let i = str.length-1;
for(;i>=0;i--){
if(str[i] === ' ') break;
}
return str.length - 1 -i;
}
console.log(getLastWordLenghth(lineString));2、计算某字符出现次数
使用哈希表，需要注意的是需要考虑不区分大小写以及
let line1 = readline();
let line2 = readline();
function getHashMap(str){
let map = {};
for(let i = 0;i<str.length;i++){
let code = str[i].toLocaleUpperCase()
if(code in map){
map[code]++;
}else{
map[code] = 1;
}
}
return map;
}
let map = getHashMap(line1);
if(map[line2.toLocaleUpperCase()]){
console.log(map[line2.toLocaleUpperCase()]);
}else{
console.log(0);
}
3、HJ4 字符串分隔
递归实现
let line = readline();
function getEightStr(str){
if(str.length>8){
console.log(str.substring(0,8));
getEightStr(str.substring(8))
}else{
console.log(str.padEnd(8,'0'));
}
}
getEightStr(line);
4、HJ5 进制转换
let line = readline();
console.log(parseInt(line,16))
5、四舍五入
注意florr ceil round的使用
let line = readline();
console.log(Math.round(line));
6、HJ9 提取不重复的整数
注意map的使用has,set, get,delete
set集合，不保存值，has, add,delete
let line = readline();
let string = line+'';
let result = '';
let map = new Map();
for(let i = string.length-1;i>=0;i--){
if(!map.has(string[i])){
result+=string[i];
map.set(string[i]);
}
}
console.log(parseInt(result));
let line = readline();
let string = line+'';
let result = '';
let set = new Set();
for(let i = string.length-1;i>=0;i--){
if(!set.has(string[i])){
result+=string[i];
set.add(string[i]);
}
}
console.log(parseInt(result));
7、HJ46 截取字符串
let string = readline();
let num = readline();
console.log(string.substring(0,num));
8、HJ58 输入n个整数，输出其中最小的k个
let line1 = readline();
line1 = line1.split(' ');
let n = parseInt(line1[0]),k = parseInt(line1[1]);
let array = readline().split(' ');
array.sort((a,b) => a-b);
let result = array.splice(0,k).join(' ');
console.log(result);
9、HJ101 输入整型数组和排序标识，对其元素按照升序或降序进行排序
let n = readline();
let array = readline().split(' ');
let flag = readline();
function sortByFlag(array,flag){
return array.sort((a,b)=>{
if(flag == 1){
return b-a;
}else{
return a-b;
}
}).join(' ');
}
console.log(sortByFlag(array,flag));
10、HJ10 字符个数统计
let string = readline();
let set = new Set();
let number = 0;
for(let i = 0;i<string.length;i++){
if(!set.has(string[i])){
set.add(string[i]);
number++;
}
}
console.log(number);
11、HJ3 明明的随机数
let n = readline();
let set = new Set();
for(let i = 0;i<=n;i++){
set.add(readline());
}
let array = Array.from(set);
array = array.sort((a,b)=>a-b).join('\n');
console.log(array);
12、质数因子
需要注意的，质因子就是这个数从2开始不断的被整除，并且质因子的平方要小于这个数
let n = parseInt(readline());
let result = [],i = 2;
for(let i = 2;i <= n && i * i <= n;i++){
while(n != i){
if(n % i == 0){
result.push(i);
n = n/i;
}else{
break;
}
}
}
if(n!=1){
result.push(n);
}
console.log(result.join(' '));
12、HJ8 合并表记录
let n = readline();
let map = {};
for(let i = 0;i<n;i++){
let line = readline().split(' ');
if(map[line[0]]){
let old = map[line[0]]
map[line[0]] = (old + +line[1]);
}else{
map[line[0]] = (+line[1]);
}
}
let result = '';
for(let item in map){
result = result + item +' '+map[item] +'\n';
}
console.log(result);
13、HJ11 数字颠倒
let number = readline()+'';
number = number.split('');
console.log(number.reverse().join(''))
14、HJ12 字符串反转
console.log(readline().split('').reverse().join(''))
15\HJ13 句子逆序
let string = readline();
string = string.split(' ');
string = string.reverse();
console.log(string.join(' '));
16\HJ14 字符串排序
let n = readline();
let array = [];
for(let i = 0;i<n;i++){
array.push(readline());
}
array = array.sort();
console.log(array.join('\n'))
17、 求int型正整数在内存中存储时1的个数
let number = parseInt(readline());
let string = number.toString(2).split('');
let n = 0;
for(let item in string){
if(string[item] == 1){
n++;
}
}
console.log(n);
18、HJ21 简单密码
let line = readline();
let result = ''
for(let i = 0;i<line.length;i++){
let str = line[i]
if(str >= 'A' && str < 'a'){
//大写字母 转小写然后+1
str = str.toLocaleLowerCase();
let code = str.charCodeAt();
if(code < 'z'.charCodeAt()){
result += String.fromCharCode(code+1) ;
}else{
result += 'a'
}
}else if(str >= 'a' && str <= 'z' ){
//小写字母
if(str == 'a' || str == 'b' || str == 'c'){
result += '2';
}else if(str == 'd' || str == 'e' || str == 'f'){
result += '3';
}else if(str == 'g' || str == 'h' || str == 'i'){
result += '4';
}else if(str == 'j' || str == 'k' || str == 'l'){
result += '5';
}else if(str == 'm' || str == 'n' || str == 'o'){
result += '6';
}else if(str == 'p' || str == 'q' || str == 'r' || str == 's'){
result += '7';
}else if(str == 't' || str == 'u' || str == 'v'){
result += '8';
}else{
result += '9';
}
}else{
//数字 原样输出
result += str
}
}
console.log(result);
19、HJ17 坐标移动
let string = readline();
string = string.split(';');
let x = 0,y = 0;
for(let i in string){
let s = string[i];//获取当前坐标
let q = s[0];
let p = +(s.substring(1));
if(!isNaN(p) && s.length>=2){
if(q == 'A'){
x -= p;
}else if(q == 'D'){
x += p;
}else if(q == 'W'){
y += p;
}else if(q == 'S'){
y -= p;
}
}
}
console.log(x+','+y)
20、HJ20 密码验证合格程序
while(line = readline()){
//循环读入
console.log(validate(line))
}
function validate(str){
let result = 'NG';
if(str.length > 8 && typeTest(str) && !isRepeat(str)){
result = 'OK'
}
return result;
}
function isRepeat(str){
for(let i = 0;i<str.length - 3;i++){
let sub = str.substring(i,i+3);
if(str.lastIndexOf(sub) > i){
return true;
}
}
}
function typeTest(str){
let num = 0;
if(/[a-z]/.test(str)){
num++;
}
if(/[A-Z]/.test(str)){
num++;
}
if(/[0-9]/.test(str)){
num++;
}
if(/[^0-9a-zA-z]/.test(str)){
num++;
}
if(num>=3){
return true
}else{
return false;
}
}
21HJ23 删除字符串中出现次数最少的字符
let map = [];
let string = readline();
for(let i = 0;i<string.length;i++){
if(map[string[i]]){
map[string[i]] = map[string[i]] + 1;
}else{
map[string[i]] = 1;
}
}
let min = 20
for(let item in map){
let v = map[item]
if(v < min){
min = v
}
}
for(let item in map){
if(map[item] == min){
let reg = new RegExp(item,'g');
string = string.replace(reg,'')
}
}
console.log(string)
HJ26 字符串排序
while(line = readline()){
let arr = line.split('');
let result = [];
for(let i = 0;i<26;i++){
//根据字母表进行排序，不区分大小写
for(let j = 0;j<arr.length;j++){
if(arr[j].charCodeAt(0) == 65 +i || arr[j].charCodeAt(0) == 97+i){
result.push(arr[j])
}
}
}
for(let i =0;i<arr.length;i++){
if(/[^a-zA-Z]/g.test(arr[i])){
result.splice(i,0,arr[i])
}
}
console.log(result.join(''))
}
HJ35 蛇形矩阵
let n = readline()
let result = []
for(let i = 0;i<n;i++){
let array = new Array(n-i)
for(let j = 0;j<n-i;j++){
if(i == 0){
if(j == 0){
array[0] = 1
}else{
array[j] = array[j-1]+j+1
}
}else{
array[j] = result[i-1][j+1] -1;
}
}
result.push(array);
console.log(array.join(' '));
}
HJ58 输入n个整数，输出其中最小的k个
let line1 = readline().split(' ');
let array = readline().split(' ');
let n = line1[0],k = line1[1];
console.log(array.sort((a,b)=>a-b).slice(0,k).join(' '))
