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1587677649.txt

/**
 * @param {number[][]} intervals
 * @return {number[]}
 */
var findRightInterval = function(intervals) {
    // collecting and sort tne ends with their index
    const starts = intervals.map(([start], index) => ({ start, index })).sort((a, b) => a.start - b.start)
    
    return intervals.map(([_, end]) => {
        const startIndex = findMinimumStart(starts, end)
        return startIndex === -1 ? -1 : starts[startIndex].index
    })
};

// lower bound
function findMinimumStart(starts, target) {
    let li = 0
    let ri = starts.length-1
    
    while(li+1 < ri) {
        const mi = Math.floor((li+ri)/2)
        if (starts[mi].start < target) {
            li = mi
        } else {
            ri = mi
        }
    }
    
    if (starts[ri].start < target || starts[li].start > target) return -1
    
    return starts[li].start >= target ? li : ri
}