1. 查找 最大 不含重复字符 子字符串AC, 思路：窗口遍历
var readline = require('readline');
const rl = readline.createInterface({
input: process.stdin,
output: process.stdout,
terminal: false
});
rl.on('line', function (line) {
var str = line.trim();
var tmp = '', maxSubStr = tmp, start = 0;
for(var i = 0; i < str.length; i++){
var j = tmp.search(str[i]);
if(j === -1){
tmp += str[i];
}else{
if(tmp.length > maxSubStr.length){
maxSubStr = tmp;
}
start += j + 1
tmp = str.slice(start, i + 1);
}
}
if(tmp.length > maxSubStr.length){
maxSubStr = tmp;
}
console.log(maxSubStr.length);
rl.close();
});
2.分几个部门未AC，笔试完后写的：
var readline = require('readline');
const rl = readline.createInterface({
input: process.stdin,
output: process.stdout,
terminal: false
});
var M = 0;
var curLine = 0;
var input = [];
rl.on('line', function (line) {
if(curLine === 0){
M = parseInt(line.trim());
}else{
input.push(line.trim().split(' '));
if(curLine === M){
console.log(func(input));;
rl.close();
}
}
curLine++;
});
function func(input){
var cnt = 0;
for(var i = 0; i < input.length; i++){
for(var j = 0; j < input[0].length; j++){
if(input[i][j] == 1){
visit(input, i, j);
cnt++;
}
}
}
return cnt;
}
function visit(input, i, j){
input[i][j] = 0;
if(i-1 >= 0 && input[i-1][j] == 1){
visit(input, i-1, j);
}
if(i+1 < input.length && input[i+1][j] == 1){
visit(input, i+1, j);
}
if(j-1 >= 0 && input[i][j-1] == 1){
visit(input, i, j-1);
}
if(j+1 < input[0].length && input[i][j+1] == 1){
visit(input, i, j+1);
}
}
3.还原IP AC：暴力分段
var readline = require('readline');
const rl = readline.createInterface({
input: process.stdin,
output: process.stdout,
terminal: false
});
rl.on('line', function (line) {
var str = line.trim();
var ret = [], a, b, c, d;
if(str.length > 12){
rl.close();
}
for(var i = 1; i <= 3; i++){
if(str.length - i < 3){
break;
}
a = str.slice(0, i);
for(var j = 1; j <= 3; j++){
if(str.length - i - j < 2){
break;
}
b = str.slice(i, i + j);
for(var k = 1; k <= 3; k++){
if(str.length - i - j - k < 1){
break;
}
c = str.slice(i + j, i + j + k);
d = str.slice(i + j + k);
var tmp = [a, b, c, d].join('.');
if(/^(1\d{2,2}|2[0-4][0-9]|25[0-5]|[1-9][0-9]|[1-9])(\.(1\d{2,2}|2[0-4][0-9]|25[0-5]|[1-9][0-9]|[0-9])){3,3}$/.test(tmp)){
ret.push(tmp);
}
}
}
}
console.log(ret.length);
rl.close();
});
4.是否为合理utf-8码：比较每个字节是否在给定区间（比大小）40%，不知道为什么出错了，样例有点问题：
var readline = require('readline');
const rl = readline.createInterface({
input: process.stdin,
output: process.stdout,
terminal: false
});
var curLine = 0;
var bytes = 0;
var input = [];
rl.on('line', function (line) {
if(curLine === 0){
bytes = parseInt(line.trim());
if(bytes > 4){
console.log(0);
rl.close();
}
}else{
input = line.trim().split(' ');
for(var i = 0; i < bytes; i++){
input[i] = parseInt(input[i]);
}
if(bytes == 1){
if(input[0] > 127 || input[0] < 0){
console.log(0);
rl.close();
}else{
console.log(1);
rl.close();
}
}else if(bytes > 1){
var max = parseInt((new Array(bytes + 1)).join('1') + '0' + (new Array(8 - bytes)).join('1'), 2);
var min = parseInt((new Array(bytes + 1)).join('1') + '0' + (new Array(8 - bytes)).join('0'), 2);
if(input[0] > max || input[0] < min){
console.log(0);
rl.close();
}else{
var max = 191;
var min = 127;
for(var i = 1; i < bytes; i++){
if(input[i] > max || input[i] < min){
console.log(0);
rl.close();
}
}
console.log(1);
rl.close();
}
}
}
curLine++;
});
5.抖音网红AC：反向建立有向图，逐个dfs，dfs返回路径等于人数，则计数加一
var Graph = (function () {
function Graph(v) {
this.vertices = v;
this.edges = 0;
this.adj = [];
this.marked = [];
for (var i = 0; i < this.vertices; i++) {
this.adj[i] = [];
this.marked[i] = false;
}
}
Graph.prototype.addEdge = function (v, w) {
this.adj[v].push(w);
this.edges += 1;
}
function _dfs(v, path) {
this.marked[v] = true;
if (this.adj[v] != undefined) {
path.push(v);
}
this.adj[v].forEach(element => {
if (!this.marked[element]) {
_dfs.call(this, element, path);
}
});
}
Graph.prototype.dfs = function (v) {
for (var i = 0; i < this.vertices; i++) {
this.marked[i] = false;
}
var path = [];
_dfs.call(this, v, path);
return path;
}
return Graph;
})();
var readline = require('readline');
const rl = readline.createInterface({
input: process.stdin,
output: process.stdout,
terminal: false
});
var N, M;
var curLine = 0;
var g;
rl.on('line', function (line) {
if (curLine === 0) {
N = parseInt(line.trim());
g = new Graph(N + 1);
} else if (curLine === 1) {
M = parseInt(line.trim());
}else if(curLine === 2){
var arr = line.trim().split(' ');
for (var i = 0; i < M * 2; i+=2) {
arr[i] = parseInt(arr[i]);
arr[i + 1] = parseInt(arr[i + 1]);
g.addEdge(arr[i + 1], arr[i]);
}
var cnt = 0;
for (var i = 1; i <= N; i++) {
var tmp = g.dfs(i);
if(tmp.length === N){
cnt++;
}
}
console.log(cnt);
rl.close();
}
curLine++;
});