Problem:
Score : 400 points

Problem Statement

One day, Snuke was given a permutation of length N, a_1, a_2, ..., a_N, from his friend.

Find the following:

Constraints

1 ≦ N ≦ 200,000

(a_1, a_2, ..., a_N) is a permutation of (1, 2, ..., N).

Input

The input is given from Standard Input in the following format:

N
a_1 a_2 ... a_N

Output

Print the answer.

Note that the answer may not fit into a 32-bit integer.

Sample Input 1

3
2 1 3

Sample Output 1

9

Sample Input 2

4
1 3 2 4

Sample Output 2

19

Sample Input 3

8
5 4 8 1 2 6 7 3

Sample Output 3

85

Solution in JavaScript (node.js v5.12) (judge verdict: Time Limit Exceeded)

'use strict';

const lines = require('fs').readFileSync('/dev/stdin', 'utf8').trim().split('\n');
const N = Number(lines[0]);
const A = lines[1].split(' ').map(Number);

let indices = [];
for (let i = 0; i < N; i++) {
	indices[indices.length] = i;
}

indices = indices.sort((a, b) => A[a] - A[b]);

let sum = 0;

function main(left, right, index) {
	if (left > right || index > N) return;
	
	let i = index;
	while (indices[i] < left || indices[i] > right) i++;
	if (index > N) return;
	
	sum += A[indices[i]] * (indices[i] - left + 1) * (right - indices[i] + 1);
	main(left, indices[i] - 1, i + 1);
	main(indices[i] + 1, right, i + 1);
}

main(0, N - 1, 0);

console.log(sum);