js 二分尋找的實現

js 二分尋找的實現

1.遞迴實現

function binarySearch(data, dest, start, end){    var end = end || data.length - 1,        start = start || 0,        m = Math.floor((start + end) / 2);    if(data[m] == dest){        return m;    }    if(dest < data[m]){        return binarySearch(data, dest, 0, m-1);    }else{        return binarySearch(data, dest, m+1, end);    }      return false;}var arr = [-34, 1, 3, 4, 5, 8, 34, 45, 65, 87];binarySearch(arr,4);//3

2.非遞迴實現

function binarySearch(data, dest){    var h = data.length - 1,        l = 0;    while(l <= h){        var m = Math.floor((h + l) / 2);        if(data[m] == dest){            return m;        }        if(dest > data[m]){            l = m + 1;        }else{            h = m - 1;        }    }      return false;}var arr = [-34, 1, 3, 4, 5, 8, 34, 45, 65, 87];binarySearch(arr,4);//3