QingLong/src/main/java/UnitTest/TestC.java

package UnitTest;

import com.dsideal.QingLong.Util.CommonUtil;

import java.util.Arrays;

public class TestC {

    public static int maxSumTwoNoOverlap(int[] nums, int firstLen, int secondLen) {
        int n = nums.length;
        int[] prefixSum = new int[n + 1];
        for (int i = 1; i <= n; i++) {
            prefixSum[i] = prefixSum[i - 1] + nums[i - 1];
        }
        int maxSum = 0;
        int[] maxSumLeft = new int[n];
        int[] maxSumRight = new int[n];
        int maxLeft = 0, maxRight = 0;
        for (int i = firstLen - 1; i <= n - secondLen; i++) {
            int sum = prefixSum[i + 1] - prefixSum[i - firstLen + 1];
            if (sum > maxLeft) {
                maxLeft = sum;
            }
            maxSumLeft[i] = maxLeft;
        }
        for (int i = n - secondLen; i >= firstLen - 1; i--) {
            int sum = prefixSum[i + secondLen] - prefixSum[i];
            if (sum >= maxRight) {
                maxRight = sum;
            }
            maxSumRight[i] = maxRight;
        }
        for (int i = firstLen - 1; i <= n - secondLen; i++) {
            int sum = prefixSum[i + 1] - prefixSum[i - firstLen + 1];
            maxSum = Math.max(maxSum, sum + maxSumRight[i + 1]);
            maxSum = Math.max(maxSum, sum + maxSumLeft[i - 1]);
        }
        return maxSum;
    }






    public static void main(String[] args) {
        int[] nums1 = { 0, 6, 5, 2, 2, 5, 1, 9, 4 };
        int firstLen1 = 1;
        int secondLen1 = 2;
        System.out.println(maxSumTwoNoOverlap(nums1, firstLen1, secondLen1)); // expect 20
    }
}