LeetCode53. Maximum Subarray一種很好的做法
阿新 • • 發佈:2019-02-16
Find the contiguous subarray within an array (containing at least one number) which has the largest sum.
For example, given the array [-2,1,-3,4,-1,2,1,-5,4]
,
the contiguous subarray [4,-1,2,1]
has the largest sum = 6
.
Solution:
class Solution {
public:
int maxSubArray(vector<int>& nums) {
int sum = 0;
int val = nums[0];
for (int i = 0; i < nums.size(); i++)
{
sum += nums[i];
if (val < sum) {
val = sum;
}
if (sum < 0) {
sum = 0;
}
}
return val;
}
};
注意點:
1. val的初值是nums[0]
2. 如果val < sum 則 val = sum;
3. 如果sum小於 0 則sum重置0,但這一步是在給val賦值之後。