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 C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<bits/stdc++.h>
using namespace std;
#define inf 1e9
#define ll long long 
#define M 1000000007
#define P pair<int,int>
#define FOR(i,m,n) for(int i=m;i<n;i++)
#define rep(i,n) FOR(i,0,n)
const int vx[4] = {0,1,0,-1};
const int vy[4] = {1,0,-1,0};
#define PI 3.14159265

int n;
ll b[210000];
set<int> s;
ll ans;

int main(){
  cin>>n;
  rep(i,n){
    int a;
    cin>>a;
    b[a]=i+1;
  }

  s.insert(0);
  s.insert(n+1);
  rep(i,n){
    auto it = s.upper_bound(b[i+1]);
    ans+=i*(*it-b[i+1])*(b[i+1]-*--it);
    s.insert(b[i+1]);
  }

  cout<<ans<<endl;

  return 0;
}