Maximum Average Subarray I

1package pkg5leetcode.official75;2 3/*4 * Maximum Average Subarray I | LC 6435 * APPROACH: Fixed-size sliding window sum of length k.6 * COMPLEXITY: Time O(n), Space O(1)7 */8public class official75_LC643MaximumAverageSubarrayI {9    static double findMaxAverage(int[] nums, int k) {10        int sum = 0;11        for (int i = 0; i < k; i++) sum += nums[i];12        int best = sum;13        for (int i = k; i < nums.length; i++) {14            sum += nums[i] - nums[i - k];15            best = Math.max(best, sum);16        }17        return (double) best / k;18    }19 20    public static void main(String[] args) {21        check(Math.abs(findMaxAverage(new int[]{1,12,-5,-6,50,3}, 4) - 12.75) < 1e-9, "case1");22        check(Math.abs(findMaxAverage(new int[]{5}, 1) - 5.0) < 1e-9, "case2");23        System.out.println("all tests passed");24    }25 26    static void check(boolean cond, String name) {27        if (!cond) throw new AssertionError("FAILED: " + name);28        System.out.println("  PASS " + name);29    }30}