OJ在线编程常见输入输出练习场

ACM模式下分V8和node.js

node.js=V8+内置基本模块，相当于java中的JRE=JVM+java标准库

node就是带有能操作IO和网络库的V8引擎，提供了很多可调用的API使得JavaScript能够读写文件，网络请求，系统信息等操作。对V8引擎进行了封装，执行JavaScript的速度更快，性能更好

不定行，定数目输入计算

//v8
while(line = readline()) {//不断读取整行
    let lines = line.split(' ').map(Number);//字符串转字符数组再转成Number格式
    let a = lines[0];
    let b = lines[1];
    console.log(a + b);
}

//node.js
let readline = require('readline');
const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});
rl.on('line', function(line) {
        let lines = line.split(' ').map(Number);
        console.log(lines[0] + lines[1]);
});

部分行参与计算+输入单个数字

//V8
let n = parseInt(readline());//读取一行，转数字
while(line = readline()) {//不断读入整行
    let lines = line.split(' ').map(Number);
    let a = parseInt(lines[0]);
    let b = parseInt(lines[1]);
    console.log(a + b);
}

//node.js
let readline = require('readline');
const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});
let num = 0;
rl.on('line', function(line) {
    if(num === 0) {
        num = parseInt(line);
    } else {
        let [x, y] = line.split(' ').map(Number);
        console.log(x + y);
    }
});

终止输入判断(多个数字)

//V8
while(line = readline()) {
    let lines = line.split(' ');
    let a = parseInt(lines[0]);//可以用map将数组转数字，也可以每个数字单独转int
    let b = parseInt(lines[1]);
    if(a === 0 && b === 0) break;//终止判断
    print(a + b);//输出可以用print也可以用console.log
}

//node.js
let readline = require('readline');
const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});
rl.on('line', function(line){
    let [x, y] = line.split(' ').map(Number);
    if(x === 0 && y === 0) return;
    console.log(x + y);
})

终止输入判断(单个数字)

//V8
while(line = readline()) {
    let lines = line.split(' ').map(Number);//转数字数组
    if(lines[0] === 0) break;//终止判断
    let res = lines.slice(1).reduce((sum, cur) => {
        return sum + cur;
    })
    print(res);
}

//node.js
const readline = require('readline');
const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});
rl.on('line', function(line) {
    let arr = line.split(' ').map(Number);
    if(arr[0] === 0) return;
    console.log(arr.slice(1).reduce((sum, cur) => sum + cur));
})

定行，不定数目输入计算

//V8
let n = parseInt(readline());
while(n--) {//读取n行
    let line = readline().split(' ').map(Number);
    let res = line.slice(1).reduce((sum, cur) => {
        return sum + cur;
    })//计算从第二个数字开始到最后的和
    print(res);
}

//node.js
const readline = require('readline');
const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});
let t = 0;
rl.on('line', function(line) {
    if(t === 0) t = parseInt(line);
    else {
        let arr = line.split(' ').map(Number);
        console.log(arr.slice(1).reduce((sum, cur) => sum + cur));
    }
})

根据每行第一个数字决定该行需要计算的数量

//V8
while(line = readline()){
    let lines = line.split(' ').map(Number);
    let res = 0;
    for(let i = 1;i <= lines[0]; i++){//也可以像上一题一样直接用slice + reduce
        res += lines[i];
    }
    console.log(res);
}

//node.js
const readline = require('readline');
const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});
rl.on('line', function(line) {
    let arr = line.split(' ').map(Number);
    console.log(arr.splice(1).reduce((sum, cur) => sum + cur));
})

不定行，不定数目输入计算

//V8
while(line = readline()) {
    let lines = line.split(' ').map(Number);
    let res = lines.reduce((sum, cur) => {
        return sum + cur;
    });
    print(res);
}

//node.js
const readline = require('readline');
const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});
rl.on('line', function(line) {
    let arr = line.split(' ').map(Number);
    console.log(arr.reduce((sum, cur) => sum + cur));
})

单行字符串排序输出

//V8
let n = parseInt(readline());
let lines = readline().split(' ');//转成数组后再用sort()方法
console.log(lines.sort().join(' '));

//node.js
const readline = require('readline');
const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});
let n = 0;
rl.on('line', function(line) {
    if(n === 0) n = parseInt(line);
    else {
        let str = line.split(' ').sort().join(' ');
        console.log(str);
    }
    
})

多行字符串各自排序空格分隔输出

//V8
while(line = readline()) {//读取多行
    let lines = line.split(' ');
    console.log(lines.sort().join(' '));
}

//node.js
const readline = require('readline');
const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});
rl.on('line', function(line) {
    let str = line.split(' ').sort().join(' ');
    console.log(str); 
})

多行字符串各自排序逗号分隔输出

//V8
while(line = readline()) {
    let lines = line.split(',');
    let res = lines.sort().join(',');
    print(res);
}

//node.js
const readline = require('readline');
const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});
rl.on('line', function(line) {
    let str = line.split(',').sort().join(',');
    console.log(str); 
})