用lua从写一次最大子数组问题

这回由于Lua 的语法比较强大，所以直接写出代码 别的不多说了，我们可以看到lua写这种逻辑是多么有快感。可以返回多个值，使算法看起来是这么的自然。

附上源代码：

function FIND_CROSSING_SUBARRAY (A,low,mid,high)
	local left_sum = -10000;
	local sum = 0;
	local max_left;
	
	local i;
	for i= mid,-1 do
		sum = sum + A[i];
		if sum>left_sum then
			left_sum = sum;
			max_left = i;
		end	
	end
	
	local right_sum = -10000;
	local sum = 0;
	local max_right;
	
	for j = (mid+1),high,1 do
		sum = sum + A[j];
		if sum >right_sum then
		right_sum = sum;
		max_right = j;	
		end
	end
	return max_left,max_right,left_sum+right_sum
end




function FIND_MAXIMUM_SUBARRAY (A,high)
	
	if high == low then
		return low,A[low]	
	else
		local mid = math.floor((low+high)/2);  


		local left_low,left_high,left_sum = FIND_MAXIMUM_SUBARRAY(A,mid);


		local right_low,right_high,right_sum= FIND_MAXIMUM_SUBARRAY(A,mid+1,high);


		local cross_low,cross_high,cross_sum= FIND_CROSSING_SUBARRAY(A,high);
		
		
		if left_sum>=right_sum then
			if left_sum>=cross_sum then
				return left_low,left_sum
			end
		end
		
		if(right_sum>=left_sum)then
			if (right_sum>=cross_sum)  then
				return right_low,right_sum
			end
		end
		
		return cross_low,cross_sum
	end
end


B={-100,79,89,201,-211,98,99,304,-432};
local left,right,maxvalue= FIND_MAXIMUM_SUBARRAY(B,1,10);
print(left," ",maxvalue);