在有序数组中查找两个数，使得它们的和正好是输入的那个数字。时间复杂度O(n)

<script type="text/javascript">

function getCal(numbers,calValue){
for(var i=0,j=numbers.length-1;i<j;){
var start = numbers[i];
var end = numbers[j];
if(start+end==calValue){
alert(start+"+"+end);
i++;
j--;
}else if(start+end<calValue){
i++;
}else if(start+end>calValue){
j--;
}
}
}

var numbers = [1,3,4,5,12,15,18,19,21,25,31];
var calValue = 22;
getCal(numbers,calValue);
</script>