Question

最小尺寸子阵列总和问题：

给定n个正整数和正整数s的数组，找到一个和≥s的子阵列的最小长度。如果没有，则返回0.

例如，给定数组[2,3,1,2,4,3]和s = 7，子阵列[4,3]在问题约束下具有最小长度。

以下是我的解决方案：

public int minSubArrayLen(int s, int[] nums) {

    long sum = 0;
    int a = 0;
    if (nums.length < 1)
        return 0;
    Arrays.sort(nums);

    for (int i = nums.length-1; i >= 0; i--) {
        sum += nums[i];
        a++;
        if (sum>=s)
            break;
    }

    if (sum < s) {
        return 0;
    }

    return a;
}

此解决方案未被接受，因为它没有通过以下测试用例：

697439

[5334,6299,4199,9663,8945,3566,9509,3124,6026,6250,7475,5420,9201,9501,38,5897,4411,6638,9845,161,9563,8854,3731， 5564,5331,4294,3275,1972,1521,2377,3701,6462,6778,187,9778,758,550,7510,6225,8691,3666,4622,9722,8011,7247,575,5431,4777,4032， 8682,5888,8047,3562,9462,6501,7855,505,4675,6973,493,1374,3227,1244,7364,2298,3244,8627,5102,6375,8653,1820,3857,7195,7830， 4461,7821,5037,2918,4279,2791,1500,9858,6915,5156,970,1471,5296,1688,578,7266,4182,1430,4985,5730,7941,3880,607,8776,1348， 2974,1094,6733,5177,4975,5421,8190,8255,9112,8651,2797,335,8677,3754,893,1818,8479,5875,1695,8295,7993,7037,8546,7906,4102， 7279,1407,2462,4425,2148,2925,3903,5447,5893,3534,3663,8307,8679,8474,1202,3474,2961,1149,7451,4279,7875,5692,6186,8109,7763， 7798,2250,2969,7974,9781,7741,4914,5446,1861,8914,2544,5683,8952,6745,4870,1848,7887,6448,7873,128,3281,794,1965,7036,8094， 1211,9450,6981,4244,2418,8610,8681,2402,2904,7712,3252,5029,3004,5526,6965,8866,2764,600,631,9075,2631,3411,2737,2328,652,494,6556， 9391,4517,8 934,8892,4561,9331,1386,4636,9627,5435,9272,110,413,9706,5470,5008,1706,7045,9648,7505,6968,7509,3120,7869,6776,6434,7994,5441， 288,492,1617,3274,7019,5575,6664,6056,7069,1996,9581,3103,9266,2554,7471,4251,4320,4749,649,2617,3018,4332,415,2243,1924,69， 5902,3602,2925,6542,345,4657,9034,8977,6799,8397,1187,3678,4921,6518,851,6941,6920,259,4503,2637,7438,3893,5042,8552,6661， 5043,9555,9095,4123,142,1446,8047,6234,1199,8848,5656,1910,3430,2843,8043,9156,7838,2332,9634,2410,2958,3431,4270,1420,4227， 7712,6648,1607,1575,3741,1493,7770,3018,5398,6215,8601,6244,7551,2587,2254,3607,1147,5184,9173,8680,8610,1597,1763,7914,3441， 7006,1318,7044,7267,8206,9684,4814,9748,4497,2239]

预期答案是132，但我的输出是80。

有没有人知道我的算法/代码出了什么问题？

Answer 1

我将简单解释逻辑中的缺陷，而不是给出正确的逻辑来处理问题陈述

您正在按特定顺序获取数字，然后添加它们以进行比较。很容易的情况可能是不同的，你以随机顺序取数字来得到确切的总和。

例如[2,3,1,2,4,3]和s = 7.

根据您的逻辑步骤1-＆gt;对数字进行排序，得到[1,2,2,3,3,4] 步骤2-＆gt;你选择最后2个数字（3,4）得到你的总和7

让我们将总和改为8 从步骤2-＆gt;你得到3 + 3 + 4 = 10所以你打破了循环。完成此步骤后，返回a = 2

这里的缺陷是4 + 3 + 1也会使你的逻辑跳过8个。同样的方式3 + 3 + 2也可以达到8的解决方案。

对数组进行排序是逻辑本身的第一个缺陷。如果您考虑现有安排的子阵列，排序会改变安排，因此您永远无法获得预期的解决方案。

最小尺寸子阵列总和与排序

1 个答案: