这段代码是关于算法和数据结构的。这段代码运行得很好,我只是有一些问题,因为我似乎不明白两点。所以我的问题是:
哪些信息在计数数组中?
while循环多久执行一次?
public class CountingSort {
public static void main(String[] args) {
int[] m1 = { 1, 17, 3, 1, 4, 9, 4, 4 };
System.out.println("unsorted:");
output(m1);
int min1 = rangeMin(m1);
int max1 = rangeMax(m1);
countingSort(m1, min1, max1);
System.out.println("sorted:");
output(m1);
int[] m2 = { -1, 13, 3, -1, -4, 9, -4, 4 };
System.out.println("unsorted:");
output(m2);
int min2 = rangeMin(m2);
int max2 = rangeMax(m2);
countingSort(m2, min2, max2);
System.out.println("sorted:");
output(m2);
}
public static void output(int[] a) {
for (int i = 0; i < a.length; i++) {
System.out.print(a[i] + ", ");
}
System.out.println();
}
public static int rangeMin(int[] a) {
int minimum = a[0];
for (int i = 1; i < a.length; i++) {
if (a[i] < minimum)
minimum = a[i];
}
return minimum;
}
public static int rangeMax(int[] array) {
int maximum = array[0];
for (int i = 1; i < array.length; i++) {
if (array[i] > maximum)
maximum = array[i];
}
return maximum;
}
public static void countingSort(int[] array, int rangeMin, int rangeMax) {
int[] countingArray = new int[rangeMax - rangeMin + 1];
for (int i : array) {
countingArray[i - rangeMin]++;
}
int c = 0;
for (int i = rangeMin; i <= rangeMax; i++) {
while (countingArray[i - rangeMin] > 0) {
array[c] = i;
c++;
countingArray[i - rangeMin]--;
}
}
}
}
1条答案
按热度按时间xkrw2x1b1#
CountingSort
有O(n)
时间和空间的复杂性。迭代(即使用for loop
)两次。