标签：
同义词 二分查找法一般指二分查找
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
|
def binarySearch(lists,select): is_none=False iflists!=[]: cen_num=len(lists)/2 tlag=lists[cen_num] gt_list=lists[0:cen_num] lt_list=lists[cen_num+1:]if tlag==select: is_none=True return is_noneelif tlag>select: is_se=binarySearch(gt_list,select) if notis_se: return binarySearch(lt_list,select) return is_none elif tlag<select: is_se=binarySearch(lt_list,select)if notis_se: return binarySearch(gt_list,select)return is_none |
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
|
programjjzx(input,output);vara:array[1..10]ofinteger;i,j,n,x:integer;begin[‘输入10个从小到大的数：‘]for i:=1 to 10 do read(a[i]);[‘输入要查找的数：‘]readln(x);i:=1;n:=10;j:=trunc((i+n)/2);repeatif a[j]>x thenbeginn:=j-1;j:=trunc((i+n)/2)endelse if a[j]<x thenbegini:=j+1;j:=trunc((i+n)/2)end;until(a[j]=x)or(i>=n);{为什么是这个结束循环条件——i>n表示所查找的范围已经空了（就是没找到）}if a[j]=x thenwriteln(‘查找成功！位置是：‘,j:3)elsewriteln(‘查找失败，数组中无此元素！‘)end. |
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
|
int BinSearch(SeqList *R，int n,KeyType K){//在有序表R[0..n-1]中进行二分查找，成功时返回结点的位置，失败时返回-1int low=0，high=n-1，mid；//置当前查找区间上、下界的初值while(low<=high){if(R[low].key==K)return low;if(R[high].key==k)return high;//当前查找区间R[low..high]非空mid=low+((high-low)/2)；//使用(low+high)/2会有整数溢出的问题//（问题会出现在当low+high的结果大于表达式结果类型所能表示的最大值时，//这样，产生溢出后再/2是不会产生正确结果的，而low+((high-low)/2)不存在这个问题if(R[mid].key==K)return mid；//查找成功返回if(R[mid].key<K)low=mid+1；//继续在R[mid+1..high]中查找elsehigh=mid-1;//继续在R[low..mid-1]中查找}if(low>high)return -1；//当low>high时表示所查找区间内没有结果，查找失败}//BinSeareh------------上面代码复杂难懂-----------------int bsearchWithoutRecursion(intarray[],int low,int high,int target){while(low<=high){int mid=(low+high)/2;if(array[mid]>target)high=mid-1;elseif(array[mid]<target)low=mid+1;else//findthetargetreturn mid;}//the array does not contain the targetreturn-1;}---------------------------------------- |
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
|
intbinary_search(constintarr[],intlow,inthigh,intkey){int mid=low+(high-low)/2;if(low>high)return -1;else{if(arr[mid]==key)return mid;else if(arr[mid]>key)return binary_search(arr,low,mid-1,key);elsereturn binary_search(arr,mid+1,high,key);}} |
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
|
public static int binarySearch(Integer[] srcArray, int des) { int low = 0; int high = srcArray.length - 1; while ((low <= high) && (low <= srcArray.length - 1) && (high <= srcArray.length - 1)) { int middle = (high + low) >> 1; if (des == srcArray[middle]) { return middle; } else if (des < srcArray[middle]) { high = middle - 1; } else { low = middle + 1; } } return -1;} |
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
|
//二分查找functionbinSearch(t,v){varp=#t;varp2;varb=0;do{p2=p;p=b+math.floor((p-b)/2)//二分折半运算if(p==b)return;if(t[p]<v){//判断下限b=p;p=p2;}}while(t[p]>v)//判断上限returnt[p]==v&&p;}//测试tab={}//创建数组，每个元素都是随机数for(i=1;10;1){tab[i]=math.random(1,10000)}//插入一个已知数table.push(tab,5632)//排序table.sort(tab)io.open()io.print("数组",table.tostring(tab))io.print("使用二分查找，找到5632在位置：",binSearch(tab,5632))} |
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
|
function binsearch($x,$a){$c=count($a);$lower=0;$high=$c-1;while($lower<=$high){$middle=intval(($lower+$high)/2);if($a[$middle]>$x)$high=$middle-1;elseif($a[$middle]<$x)$lower=$middle+1;elsereturn $middle;}return -1;} |
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
|
int binSearch(const int *Array,int start,int end,int key){ int left,right; int mid; left=start; right=end; //注释中为递归算法，执行效率低，不推荐 /* if(key<Array[mid]) { return(binSearch(Array,left,mid,key)); } else if(key>Array[mid]) { return(binSearch(Array,mid+1,right,key)); } else return mid; */ while(left<=right) { mid=(left+right)/2; if(key==Array[mid]) return mid; else if(key<Array[mid]) right=mid-1; else if(key>Array[mid]) left=mid+1; } return -1; //找不到就返回-1} |
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
|
publicstaticfunctionbinSearch(list:Array,low:int,high:int,key:int):int{if(low>high)return-1;varmid:int=low+int((high-low)/2);varindex:int=-1if(list[mid]==key){index=mid;}elseif(list[mid]<key){low=mid+1;index=binSearch(list,low,high,key);}else{high=mid-1;index=binSearch(list,low,high,key);}returnindex;} |
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
|
varArr=[3,5,6,7,9,12,15];functionbinary(find,arr,low,high){if(low<=high){if(arr[low]==find)returnlow;if(arr[high]==find)returnhigh;varmid=Math.ceil((high+low)/2);if(arr[mid]==find){returnmid;}elseif(arr[mid]>find){returnbinary(find,arr,low,mid-1);}else{returnbinary(find,arr,mid+1,high);}}return-1;}binary(15,Arr,0,Arr.length-1); |
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
|
/*二分查找：前提，该数组已经是一个有序数组，必须先排序，再查找。*/functionbinarySearch(&$array,$findVal,$leftIndex,$rightIndex){$middleIndex=round(($rightIndex+$leftIndex)/2);if($leftIndex>$rightIndex){echo‘查无此数<br/>‘;return;}if($findVal>$array[$middleIndex]){binarySearch($array,$findVal,$middleIndex+1,$rightIndex);}elseif($findVal<$array[$middleIndex]){binarySearch($array,$findVal,$leftIndex,$middleIndex-1);}else{echo"找到数据:index=$middleIndex;value=$array[$middleIndex]<br/>";if($array[$middleIndex+1]==$array[$middleIndex]&&$leftIndex<$rightIndex){binarySearch($array,$findVal,$middleIndex+1,$rightIndex);}if($array[$middleIndex-1]==$array[$middleIndex]&&$leftIndex<$rightIndex){binarySearch($array,$findVal,$leftIndex,$middleIndex-1);}}} |
标签：
原文地址：http://www.cnblogs.com/yg6405816/p/5479524.html
