[英]Procedure to sort a two dimensional int array depending on column
The array I have before and how we want it after the sorting:我之前拥有的数组以及排序后我们想要的数组:
Before:之前:
Box Weight Priority
1 50 5
2 30 8
3 90 6
4 20 7
5 80 9
After:之后:
Box Weight Priority
3 90 6
5 80 9
1 50 5
2 30 8
4 20 7
We work in the int matrix:我们在 int 矩阵中工作:
data= new int[BoxNumber][3];
The sorting is based in the second column Weight.排序基于第二列权重。 I am looking for a procedure that sorts the data array.
我正在寻找对数据数组进行排序的过程。
public void sortC(int[][] temp)
{
if (temp.length >= 2)
{
for (int i = 1; i <= temp.length - 1; i++)
{
int[] hold = temp[i];
int[] holdP = temp[i-1];
int j = i;
while (j > 0 && hold[1] < holdP[1]) // 1 represents the reference of sorting
{
hold = temp[j];
holdP = temp[j-1];
temp[j] = holdP;
temp[j-1] = hold;
j--;
}
}
}
}
sortC(data);
I tried this one, but unfortunately it doesn't give a right sorting I couldn't figure out the pickle.我试过这个,但不幸的是它没有给出正确的排序,我无法弄清楚泡菜。
Use java.util.Arrays.sort
with a custom Comparator
.将
java.util.Arrays.sort
与自定义Comparator
。
int[][] temp = { { 1, 50, 5 }, { 2, 30, 8 }, { 3, 90, 6 },
{ 4, 20, 7 }, { 5, 80, 9 }, };
Arrays.sort(temp, new Comparator<int[]>() {
@Override
public int compare(int[] o1, int[] o2) {
return Integer.compare(o2[1], o1[1]);
}
});
As shmosel mentioned below , with Java 8, you can use:作为shmosel 下文提到的,与Java 8中,您可以使用:
Arrays.sort(temp, Comparator.comparingInt(arr -> arr[1]));
You can do this instead of writing your own sorting algorithm:您可以这样做而不是编写自己的排序算法:
int[][] n = new int[10][];
//init your array here
List<int[]> ints = Arrays.asList(n);
Collections.sort(ints, new Comparator<int[]>() {
@Override
public int compare(int[] o1, int[] o2) {
return o1[1] - o2[1]; // compare via second column
}
});
and if you want make it array again:如果你想让它再次排列:
int[][] result = ints.toArray(n);
Arrays.sort(boxTypes, (a, b) -> b[1] - a[1]); Arrays.sort(boxTypes, (a, b) -> b[1] - a[1]);
or Using a priority queue或使用优先队列
PriorityQueue<int[]> queue = new PriorityQueue<>((a, b)->b[1] - a[1]); PriorityQueue<int[]> queue = new PriorityQueue<>((a, b)->b[1] - a[1]);
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