Function splitArray

javascript/0410-split-array-largest-sum.js:10–40

(nums, k)

 * @return {number}
 */
var splitArray = function (nums, k) {
    let left = Math.max(...nums);
    let right = nums.reduce((acc, num) => acc + num, 0);
    let result = right;
    while (left <= right) {
        const mid = (left + right) >> 1;
        if (canSplit(mid)) {
            result = mid;
            right = mid - 1;
        } else {
            left = mid + 1;
        }
    }

    function canSplit(largest) {
        let splitCount = 0;
        let currSum = 0;

        for (let i = 0; i < nums.length; i++) {
            currSum += nums[i];
            if (currSum > largest) {
                currSum = nums[i];
                splitCount++;
            }
        }

        return splitCount + 1 <= k;
    }

    return result;
};