贴一下第一题吃烧饼后来的想法，时间复杂度O(n)......（目前测试用例是对的） Scanner in = new Scanner(System.in); int n = in.nextInt(); int[] nums = new int[n]; for (int i=0;i<n;i++){ nums[i] = in.nextInt(); } int count = 0; int min = nums[0]; for (int i=0;i<nums.length;i++){ if (nums[i]<min) { min = nums[i]; } count += min; } System.out.println(count);