线性查找、二分法 JAVA、Python

线性查找：
JAVA

public class TestSearch {
    public static void main(String[] args){
        int[] arr =new int[]{1,2,5,4,6,8,7,0};
        int target = 0;
        int index = -1;

        for (int i =0;i<arr.length;i++){
            if (arr[i]==target){
                index = i;
                break;
            }
        }
        System.out.println("index:"+index);
    }
}

Python

def linearsearch(arr,value):
    index = -1
    for i in range(len(arr)):
        if arr[i] == value:
            index = i
            break
    print(index)
num_list = [5,9,7,1,3,6]
linearsearch(num_list,6)

二分法
JAVA

public class BinarySearch {
    public static void main(String[] args){
        int[] arr = new int[]{1,2,3,4,5,6,7,8,9};
        int target = 10;
        int begin = 0;
        int end = arr.length-1;
        int index = -1;

        while (begin<=end){
            int mid = (begin + end)/2;
            if (arr[mid]==target){
                index=mid;
                break;
            }else if(arr[mid]>target){
                end = mid-1;
            }else {
                begin = mid +1;
            }
        }
        System.out.println("index:"+index);
    }

}

Python

def BinearSearch(arr,target):
    begin = 0
    end = len(arr)-1
    index = -1
    while begin <= end:
        mid = int((begin + end)/2)
        if arr[mid] == target:
            index = mid
            break
        elif arr[mid] > target:
            end = mid -1
        else:
            begin = mid +1
    print(index)

num_list = [1,2,3,4,5,6,7,8,9]
BinearSearch(num_list,9)