binary search

gistfile1.txt

public static int binarySearch(int[]array,int key){ //looks for the index of the element that has value key, returns index. array must be sorted 
    int min=0; //initializes min, max, guess
    int max=array.length-1;
    int guess=(min+max)/2;
    while(array[guess]!=key){ //keeps on looking until key is found
      if(min==guess||max==guess){//if min=guess, max=guess, the key does not exist in the array
        return(-1);//returns -1 if key is not found
      }
      if(array[guess]>key){//you only have to search between min and guess
        max=guess;
      }
      else{//search between max and guess
        min=guess;
      }
      guess=(min+max)/2;//new value for guess-middle of the interval
    }
    return(guess);//exists the loop of key is found-returns the index
  }