constructor(inputArray, operation, operationFallback) {
    this.inputArray = inputArray;
    this.operation = operation;
    this.operationFallback = operationFallback;

    // Init array representation of segment tree.
    this.segmentTree = this.initSegmentTree(this.inputArray);

    this.buildSegmentTree();
  }
@param {number[]} inputArray
@param {function} operation - binary function (i.e. sum, min)
@param {number} operationFallback - operation fallback value (i.e. 0 for sum, Infinity for min)