weighted task scheduling

weightedTaskScheduling.js

function binarySearch (array, target, start, end) {
    var l = start || 0;
    var r = end || array.length - 1;
    while (l<=r) {
        var mid = Math.floor((l+r)/2);
        if (array[mid]==target) {
            return mid;
        } else if (array[mid]>target) {
            r = mid - 1;
        } else {
            l = mid + 1;
        }
    }
    return r;
}

function weightedIntervalScheduling(taskArray) {
    taskArray.sort(function (a,b) {
        return a.end - b.end ==0 ? a.start - b.start: a.end - b.end;
    });
    //console.log(taskArray);
    var endArray = taskArray.map(function (obj) {
        return obj.end;
    });
    //console.log(endArray);
    var pArray = [-1];
    for (var i = 1; i<taskArray.length; i++) {
        var idx = binarySearch(endArray,taskArray[i].start,0,i-1);
        pArray[i] = idx;
    }
    //console.log(pArray);
    var res = [];
    res[0] = taskArray[0].weight;
    for (var i= 1; i<taskArray.length; i++) {
        if (pArray[i]>-1) {
            res[i] = res[pArray[i]]+taskArray[i].weight;
        } else {
            res[i] = taskArray[i].weight;
        }
        res[i] = Math.max(res[i], res[i-1]);
    }
    return res[res.length-1];
}