回文数组
输入
8
51 23 52 97 97 76 23 51
输出
598

代码测试验证部分如下

        int[] arr = {51, 23, 52, 97, 97, 76, 23, 51};
        int mid = (arr.length - 1) / 2;
        int length = arr.length;
        int indexMax= arr.length-1;
        boolean flag = true;
        int res=0;
        while (mid >= 0) {
            if (length % 2 != 0 && flag) {
                res+=arr[mid];
                flag = false;
            }else{
                if (arr[mid] ==arr[indexMax-mid]) {
                    res+=arr[mid];
                    res+=arr[indexMax-mid];
                }else{
                    int pl = (arr[mid] + arr[indexMax - mid])*2;
                    res+=pl;
                }
                }
            mid--;
            }
        System.out.println(res);
        Integer reduce = IntStream.of(arr).boxed().reduce(0, (a, b) -> a + b);
        reduce+=52;
        reduce+=76;
        System.out.println("reduce:"+reduce);
    }