题解 | #17.二分查找-I#

注意：

1. left<=right

function search( nums ,  target ) {
  let left = 0, right = nums.length-1;
  while(left <= right){
    let mid =  parseInt( (left + right)/2 );
    if(nums[mid] < target){//target在右边继续查找
      left = mid+1;
    }else if(nums[mid] > target){//target在左边继续查找
      right = mid-1;
    }else{
      return mid;
    }
  }
  return -1;
}
module.exports = {
    search : search
};