Node.js) 백준 11659번: 구간 합 구하기 4

https://www.acmicpc.net/problem/11659

11659번: 구간 합 구하기 4

const input = require('fs').readFileSync('./dev/stdin').toString().trim().split('\n').map(v => v.split(' ').map(Number));
input.shift();
const arr = input.shift().reduce((r, v, i) => {
	const sum = r[r.length - 1] + v;
	r.push(sum);
	return r;
}, [0]);

console.log(input.reduce((r, v) => {
	const [i, j] = v;
	const diff = arr[j] - arr[i - 1];
	r.push(diff)
	return r;
}, []).join('\n'))