????/*?

?????*?非遞歸二分查找算法?

?????*?參數(shù):整型數(shù)組,需要比較的數(shù).?

?????*/??

????public?static?int?binarySearch(Integer[]srcArray,int?des){??

????????//第一個位置.??

????????int?low=0;??

????????//最高位置.數(shù)組長度-1,因為下標是從0開始的.??

????????int?high=srcArray.length-1;??

????????//當low"指針"和high不重復的時候.??

????????while(low<=high){??

????????????//中間位置計算,low+?最高位置減去最低位置,右移一位,相當于除2.也可以用(high+low)/2??

????????????int?middle=low+((high-low)>>1);??

????????//與最中間的數(shù)字進行判斷,是否相等,相等的話就返回對應的數(shù)組下標.??

????????if(des==srcArray[middle]){??

????????????return?middle;??

????????//如果小于的話則移動最高層的"指針"??

????????}else?if(des<srcArray[middle]){??

????????????high=middle-1;??

????????//移動最低的"指針"???

????????}else{??

????????????low=middle+1;??

????????????}??

????????}??

????????return-1;??

????????}??

??????

}??

/**?

?*?遞歸方法實現(xiàn)二分查找法.?

?*?@param?Array數(shù)組?

?*?@param?low?數(shù)組第一位置?

?*?@param?high?最高?

?*?@param?key?要查找的值.?

?*?@return?返回值.?

?*/??

int?BinSearch(int?Array[],int?low,int?high,int?key)??

{??

????if?(low<=high)??

????{??

????????int?mid?=?(low+high)/2;??

????????if(key?==?Array[mid])??

????????????return?mid;??

????????else?if(key<Array[mid])??

????????????//移動low和high??

????????????return?BinSearch(Array,low,mid-1,key);??

????????else?if(key>Array[mid])??

????????????return?BinSearch(Array,mid+1,high,key);??

????}??

????else??

????????return?-1;??

}??