minSubArrayLen.js

// Write a function called minSubArrayLen which accepts two parameters - an array of positive integers and a positive integer.

// This function should return the minimal length of a contiguous subarray of which the sum is greater than or equal to the integer passed to the function. If there isn't one, return 0 instead.
// Examples:

// minSubArrayLen([2,3,1,2,4,3], 7) // 2 -> because [4,3] is the smallest subarray
// minSubArrayLen([2,1,6,5,4], 9) // 2 -> because [5,4] is the smallest subarray
// minSubArrayLen([3,1,7,11,2,9,8,21,62,33,19], 52) // 1 -> because [62] is greater than 52
// minSubArrayLen([1,4,16,22,5,7,8,9,10],39) // 3
// minSubArrayLen([1,4,16,22,5,7,8,9,10],55) // 5
// minSubArrayLen([4, 3, 3, 8, 1, 2, 3], 11) // 2

const minSubArrayLen =(arr, val) =>{
    let start = 0;
    let total = 0;
    let end=0;
    let length = arr.length;
    let found = 0;
    while(start < arr.length){
        if(total < val){
            total += arr[end];
            end++;
        }
        else if (total >=val){
            length =  Math.min(length, end-start);
            total -= arr[start];
            start++;
            found = 1;
        }
        else{
            break;
        }
    }
    return found? length : 0;
}

console.log(minSubArrayLen([1,4,16,22,5,7,8,9,10],55));