【练内功，促成长】算法学习(3) 二分查找

代码实现

//@todo 今晚添加详细解释。

function bSearch(arr:number[], value: number):number {
      let low = 0;
      let high = arr.length - 1;
      while(low <= high) {
            let mid = ~~((low + high) / 2);
            let midValue = arr[mid];
            if (arr[mid] === value) {
                  return mid;
            } else if ( midValue > value){
                   high = mid - 1;
            } else {
                  low = mid + 1;
            }
      }
      return -1;
}