COunt the number of continous subsequences such that the sum is between

// CPP program to find number of subarrays having 
// sum in the range L to R. 
#include <bits/stdc++.h> 
using namespace std; 
  
// Function to find number of subarrays having 
// sum less than or equal to x. 
int countSub(int arr[], int n, int x) 
{ 
  
    // Starting index of sliding window. 
    int st = 0; 
  
    // Ending index of sliding window. 
    int end = 0; 
  
    // Sum of elements currently present 
    // in sliding window. 
    int sum = 0; 
  
    // To store required number of subarrays. 
    int cnt = 0; 
  
    // Increment ending index of sliding 
    // window one step at a time. 
    while (end < n) { 
  
        // Update sum of sliding window on 
        // adding a new element. 
        sum += arr[end]; 
  
        // Increment starting index of sliding 
        // window until sum is greater than x. 
        while (st <= end && sum > x) { 
            sum -= arr[st]; 
            st++; 
        } 
  
        // Update count of number of subarrays. 
        cnt += (end - st + 1); 
        end++; 
    } 
  
    return cnt; 
} 
  
// Function to find number of subarrays having 
// sum in the range L to R. 
int findSubSumLtoR(int arr[], int n, int L, int R) 
{ 
  
    // Number of subarrays having sum less 
    // than or equal to R. 
    int Rcnt = countSub(arr, n, R); 
  
    // Number of subarrays having sum less 
    // than or equal to L-1. 
    int Lcnt = countSub(arr, n, L - 1); 
  
    return Rcnt - Lcnt; 
} 
  
// Driver code. 
int main() 
{ 
    int arr[] = { 1, 4, 6 }; 
    int n = sizeof(arr) / sizeof(arr[0]); 
  
    int L = 3; 
    int R = 8; 
  
    cout << findSubSumLtoR(arr, n, L, R); 
    return 0; 
} 
// CPP program to count 
// subarrays having sum 
// less than k. 
#include <bits/stdc++.h> 
using namespace std; 
  
// Function to find number 
// of subarrays having sum 
// less than k. 
int countSubarray(int arr[], 
                  int n, int k) 
{ 
    int count = 0; 
  
    for (int i = 0; i < n; i++) { 
        int sum = 0; 
        for (int j = i; j < n; j++) { 
  
            // If sum is less than k 
            // then update sum and 
            // increment count 
            if (sum + arr[j] < k) { 
                sum = arr[j] + sum; 
                count++; 
            } 
            else { 
                break; 
            } 
        } 
    } 
  
    return count; 
} 
  
// Driver Code 
int main() 
{ 
    int array[] = { 1, 11, 2, 3, 15 }; 
    int k = 10; 
    int size = sizeof(array) / sizeof(array[0]); 
    int count = countSubarray(array, size, k); 
    cout << count << "\n"; 
}