Minimum Subarray
Given an array of integers, find the subarray with smallest sum.
Return the sum of the subarray.
Example
For [1, -1, -2, 1], return -3
Note
The subarray should contain at least one integer.
Solution: O(n) time O(1) space. one pass. Prefix Sum
public int minSubArray(ArrayList<Integer> nums) {
if (nums == null || nums.size() == 0) {
return 0;
}
int minSum = Integer.MAX_VALUE;
int sum = 0;
int maxSum = 0;
for (Integer num : nums) {
sum += num;
minSum = Math.min(minSum, sum - maxSum);
maxSum = Math.max(maxSum, sum);
}
return minSum;
}
