BinarySubarrayWithSum

class Solution {
public:

	int lessequal(vector<int>& nums, int goal) {//SLIDING WINDOW IMPLEMENTED 

		if(goal < 0) return 0;//IF NEGATIVE SUM NOT POSSIBLE 

		int n = nums.size();
		int i = 0, j = 0;
		int sum = 0;//SUM STORING VARIABLE 
		int ans = 0;//ANS =0 NO OF SUBARRAY STORING VARIABLE 

		while(j < n) {//J<N

			sum += nums[j];//SUM =SUM+NUMS[J]

			while(sum > goal) {//IF >GOAL 
				sum -= nums[i];//THEN SUBTARCT THAT ELMNT FROM SUM ...OPS EXCLUDED 
				i++;//THEN SLIDING THE WINDOW AHEAD 
			}    
			ans += j-i+1;        //STORING THE NUMBER OF SUBARRAY POSSIBILITY WITH SUM<=GOAL  
			j++;  //++ INCREMENT 
		}

		return ans;    
	}

	int numSubarraysWithSum(vector<int>& nums, int goal) {

		return lessequal(nums, goal) - lessequal(nums, goal - 1);
	}
};

// our function is giving number of subarrays with sum less or equal to goal.