<script>
//採用動態規劃法
function findGreatestSun(arr){
	var curSum, greatestSum;
	curSum = greatestSum = 0;
	var start, end;
	start = end = 0;
	//陣列中正負數都有
	for(var i = 0;i<arr.length;i++){
		curSum+= arr[i];
		if(curSum < 0){
			curSum = 0;
			start++;
		}
		if(curSum > greatestSum){
			greatestSum = curSum;
			end = i;
		}
		
	}
	//若陣列中只有非正數，則找到最大的值即為最大和
	if(greatestSum == 0){
		start = end = 0;
		for(var i = 1;i<arr.length;i++){
			greatestSum = arr[0];
			if(greatestSum < arr[i]){
				greatestSum = arr[i];
				start = end = i;
			}
		}
	}
	alert("sum:"+greatestSum +"--start:"+start+"--end:"+end);
}

var arr_a = [1, -2, 3, 10, -4, 7, 2, -5]
findGreatestSun(arr_a);
</script>