Top 150 · Kadane 算法（2 题）

class Solution {
    public int maxSubArray(int[] nums) {
        int len = nums.length;
        if(len == 1){return nums[0];}
        int pre = nums[0];
        for(int i =1;i<len;i++){
            if(pre >0){
                nums[i]+=pre;
            }
            pre = nums[i];
        }
        int ans = nums[0];
        for(int i =0;i<len;i++){
            ans = Math.max(ans,nums[i]);
        }
        return ans;
    }
}

class Solution {
    public int maxSubarraySumCircular(int[] nums) {
        int total =0;
        int maxSum =nums[0];
        int minSum =nums[0];
        int curMax = 0;
        int curMin = 0;
        for (int a : nums) {
            curMax = Math.max(curMax + a, a);
            maxSum = Math.max(maxSum, curMax);
            curMin = Math.min(curMin + a, a);
            minSum = Math.min(minSum, curMin);
            total += a;
        }
        return maxSum >0? Math.max(maxSum,total-minSum):maxSum;
    }
}