js实现的顺序搜索和二分搜索

搜索算法

1. 顺序搜索

var sequentialSearch = function (arr, value) {
    for (var i = 0; i < arr.length; i++) {
        if (value === arr[i]) {
            return i;
        }
    }
    return -1;
}
var arr = [5, 2, 9, 3, 7, 9];
console.log(sequentialSearch(arr, 9))

1. 二分搜索

var binarySearch=function (arr,item) {
    var low=0;
    var high=arr.length-1;
    var mid;
    var element;
    while(low<high){
        mid=Math.floor((low+high)/2);
        element=arr[mid];
        if(element<item){
            low=mid+1;
        }else if (element>item){
            high=mid-1;
        } else{
            return mid;
        }
    }
    return -1;
}
var sequentialSearch = function (arr, value) {
    for (var i = 0; i < arr.length; i++) {
        if (value === arr[i]) {
            return i;
        }
    }
    return -1;
}
var arr = [1,3,5,6,8,9,9];
console.log(binarySearch(arr, 9));