<p>Given an integer array <code>nums</code> and two integers <code>lower</code> and <code>upper</code>, return <em>the number of range sums that lie in</em> <code>[lower, upper]</code> <em>inclusive</em>.</p>

<p>Range sum <code>S(i, j)</code> is defined as the sum of the elements in <code>nums</code> between indices <code>i</code> and <code>j</code> inclusive, where <code>i &lt;= j</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums = [-2,5,-1], lower = -2, upper = 2
<strong>Output:</strong> 3
<strong>Explanation:</strong> The three ranges are: [0,0], [2,2], and [0,2] and their respective sums are: -2, -1, 2.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [0], lower = 0, upper = 0
<strong>Output:</strong> 1
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 10<sup>5</sup></code></li>
	<li><code>-2<sup>31</sup> &lt;= nums[i] &lt;= 2<sup>31</sup> - 1</code></li>
	<li><code>-10<sup>5</sup> &lt;= lower &lt;= upper &lt;= 10<sup>5</sup></code></li>
	<li>The answer is <strong>guaranteed</strong> to fit in a <strong>32-bit</strong> integer.</li>
</ul>

#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;
// #define int long long
#define pi pair<int , int>
#define ppi pair<pi ,int>

// int INF = INT64_MAX;
int mod = 1e9+7;

typedef tree<long long,null_type,less_equal<long long> ,rb_tree_tag,tree_order_statistics_node_update> pbds;

class Solution {
public:
    int countRangeSum(vector<int>& nums, int l, int r) {
            long long n = nums.size();
                    vector<long long> pref(n+1, 0);
                            for(int i=0;i<n;i++)pref[i+1] = pref[i] + nums[i];
                                    pbds p1;
                                            long long ans = 0;
                                                    map<long long , int> mp;
                                                            for(int i=n-1;i>=0;i--)
                                                                    {
                                                                                p1.insert(pref[i+1]);
                                                                                            mp[pref[i+1]]++;
                                                                                                        long long updt_l = (long long)pref[i] + l , updt_r = (long long)pref[i] + r;
                                                                                                                    long long less1 = (long long)p1.order_of_key(updt_l);
                                                                                                                                long long less2 = (long long)p1.order_of_key(updt_r);
                                                                                                                                            ans += (mp[updt_r] + less2 - less1);
                                                                                                                                                    }
                                                                                                                                                            return ans;
                                                                                                                                                                }
                                                                                                                                                                };
223865