//二分法排序
var arr = [1,2,3,4,5,6,7,8];
function myFunction(arr,value){
var low = 0;
var heigh = arr.length - 1;
while(low <= heigh){
var mid = parseInt((low + heigh)/2);
if (value == arr[mid]) {
return mid;
}else if(value <= arr[mid]){
heigh = mid -1;
}else if(value >= arr[mid]){
low = mid + 1
}
}
return -1;
}
alert(myFunction(arr,3));
//对称检验
var arr = [1,2,3,2,1]
function text(arr){
if(arr.length == 0 || !(arr instanceof Array)){
return false;
};
for (var i = 0; i <= arr.length; i++) {
if(arr[i] !== arr[arr.length - 1 -i]){
return false;
}
}
return true
}
console.log(text(arr))
//对称检验
var arr = [1,2,3,4,];
function myFunction(arr){
if(arr.length == 0 || !(arr instanceof Array)){
return false;
}
var low = 0;
heigh = arr.length - 1;
while(low <= heigh){
if(arr[low] != arr[heigh] ){
return false;
}
}
return true;
}
console.log(myFunction(arr))
归来仍是少年
