详细解析java算法之二分查找法的实例

packageme.geed.algorithms;
  
publicclassBinarySearch {
  
  /**
   * 从一个有序数组(如升序)中找到值为key元素
   * @param key
   * @param array
   * @return 如果找到目标元素，则返回其在数组中的索引，否则返回-1
   */
  publicstaticintfind(intkey,int[] array){
    intlow =0;
    inthigh = array.length -1;
    while(low <= high) {
      intmid = low + (high - low) /2;
      if(array[mid] > key) {
        high = mid -1;
      }elseif(array[mid] < key) {
        low = mid +1;
      }else{
        returnmid;
      }      
    }
    return-1;   
  }
    
  publicstaticvoidmain(String[] args) {
    // TODO Auto-generated method stub
    int[] array = {2,3,5,9,10,13,23,45,78,89,100,128,256};
    System.out.println("目标元素索引值："+ BinarySearch.find(9, array));    
    System.out.println("目标元素索引值："+ BinarySearch.find(26, array));
  }
  
}