对折查找

Posted 2021-01-31 tanchangsha

var brr=[1,2,3,4,5,6,7,8,9];
var start=0;
var end=brr.length-1;
while(true){
    if(start > end){
        break;
    }
    var mid=parseInt((start+end)/2);
    if(brr[mid] === 3){
        break;
    }else if(brr[mid] > 3){
        end = mid;
    }else{
        start = mid;
    }
}