如何获取2D数组中元素的索引？

int[][] triangle = {  
                              {75},
                             {87,64}, //If index is 0, then start from j = 0 in 3rd row (24, 56, 88)
                               {24, 56, 88}, // if index is 2 then start from j = 2 in 4th row (43, 45, 67, 76),  and compare 67 and 76, and find the max
                               {43, 45, 67, 76}
  };

  for (int i = 0; i < array.length - 1; i++) {
   for (int j = 0; j < array[i].length; j++) {
        int  x = triangle[i][j];
         int y = triangle[i][j + 1];
            int max = Math.max(x, y);
      if (someCondition) {
          //getTheIndexOFMaxVariable (Here If I am looking for 64 then it should give me 1 as an index)
       }
    }
 }

My question is if I am looking for element 64 then it should give me index as an 1 instead of [1][1]

我的问题是,如果我正在寻找元素64然后它应该给我索引作为1而不是[1] [1]

Is there any way I can get the index of an array like 1 instead of [1][1].

有没有什么办法可以让数组的索引像1而不是[1] [1]。

Any help is appreciated.

任何帮助表示赞赏。

2 个解决方案

#1

By converting your 2D Array int[][] to List<List<Integer>>, you can take advantage of indexOf to find the index of your max:

通过将2D Array int [] []转换为List >,您可以利用indexOf查找max的索引:

List<List<Integer>> triangle = new ArrayList<List<Integer>>();
    triangle.add(Arrays.asList(75));
    triangle.add(Arrays.asList(95, 64));

    for (List<Integer> row : triangle) {
        // you can also ask for row.indexOf(max);
        System.out.println("At row: " + triangle.indexOf(row) + " is: " + row.indexOf(64));         
    }

#2

I might be mistaken but wouldn't the index be the j variable?

我可能会弄错,但索引不是j变量吗?

Since you are looping over the array with first loop, i will contain the index of current array (relative to the parent array).

由于您使用第一个循环遍历数组,因此我将包含当前数组的索引(相对于父数组)。

But second loop iterates over the child arrays, so the index of your element will be the j.

但是第二个循环遍历子数组,因此元素的索引将是j。

int[][] triangle = {  
            {75},
            {95,64}
  };

for (int i = 0; i < array.length - 1; i++) {
   for (int j = 0; j < array[i].length; j++) {
      // notice we use j variable to access the item, since it contains the index for current
      int item = array[i][j];

      if (item == 64) {
          // your code
       }
    }
 }

EDIT:

Based on the update, I'd recommend to throw away the Math.max function because that makes you lose the track of the index. Since you only have 2 elements to compare, a simple if statement would do.

根据更新,我建议扔掉Math.max函数,因为这会让你失去索引的轨迹。由于您只有2个要比较的元素,因此可以使用简单的if语句。

int x = triangle[i][j];
int y = triangle[i][j + 1];
int max = 0;
int indexOfMax = 0;

// using >= just in case if both numbers are equal
if (x >= y) {
    max = x;
    indexOfMax = j;
} else {
    max = y;
    indexOfMax = j + 1;
}

if (someCondition) {
    // your code
}

#1