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

#include<bits/stdc++.h>
using namespace std;
int n,l[200010],r[200010],a[200010]={},top=0;
long long ans=0,st[200010]={};
inline int read()
{
	int x=0,w=0;char ch=0;
	while(!isdigit(ch)){w|=ch=='-';ch=getchar();}
	while(isdigit(ch)){x=(x<<3)+(x<<1)+(ch^48);ch=getchar();}
	return w?-x:x;
}
int main()
{
	n=read();
	for(int i=1;i<=n;i++)
		l[i]=0,r[i]=n+1;
	for(int i=1;i<=n;i++){
		a[i]=read();
		while(a[i]<a[st[top]])
			r[st[top--]]=i;
		l[i]=st[top];
		st[++top]=i;
	}
	for(int i=1;i<=n;i++)
		ans+=a[i]*(i-l[i])*(r[i]-i);
	printf("%lld\n",ans);
}