在数组中查找多个模式
我正在尝试编写一个查找数组中所有模式的java方法。 我知道有一种简单的方法可以在数组中找到模式，但是当有多个单一模式时，我的方法只输出其中一种模式。 我试图找到一种方法，但我不确定如何解决这个问题。 任何人都可以帮我找出arrays中的所有模式吗？ 谢谢。
这里是我的代码，即使存在多种模式，它也只输出一种模式。
public static int mode(int a[]){ int maxValue=0, maxCount=0; for (int i = 0; i < a.length; ++i){ int count = 0; for (int j = 0; j maxCount){ maxCount = count; maxValue = a[i]; } } return maxValue; } 好的，这是一个例子：30 30 30 34 34 23
在这组数字中，只有一种模式，即30。
30 30 30 34 34 34 23
但是在这个集合中有两种模式，30和34.我希望我的代码能够输出它们两个，而它只打印一个。 它打印只有30。
以下代码将返回包含模式的Integer[] 。 如果需要int[] ，则仍需要手动将Integer实例转换为int 。 可能不是最有效的版本，但它与您的代码紧密匹配
public static Integer[] mode(int a[]){ List modes = new ArrayList ( ); int maxCount=0; for (int i = 0; i < a.length; ++i){ int count = 0; for (int j = 0; j < a.length; ++j){ if (a[j] == a[i]) ++count; } if (count > maxCount){ maxCount = count; modes.clear(); modes.add( a[i] ); } else if ( count == maxCount ){ modes.add( a[i] ); } } return modes.toArray( new Integer[modes.size()] ); }
经过漫长的编程之夜，我终于得到了一个打印出arrays模式/模式的程序。 或者甚至会告诉你是否没有模式（例如，如果没有输入超过一次或所有输入发生的次数相同：例如1,1,2,2,3,3,4,4 ）。 该程序的一些限制是您必须输入多个数字，并且您不能输入超过10000个数字或负数（如果您想输入负数，您只需调整涉及值的所有for循环[] []数组。关于我的程序的一些很酷的事情是它打印出你的每个输入发生了多少次以及数组的模式。并且所有打印输出语法根据信息量而变化（例如。数组的模式是2;数组的模式是1和2;数组的模式是0,2,5和8）。程序中还有一个冒泡排序函数示例，适用于任何认为他们需要在他们的模式程序中使用一个分类器function。希望这有帮助，我包含了很多伪代码来帮助那些看不到我的逻辑在整个程序中如何进展的人。（仅供参考：它是java，并且是在BlueJ中编译的）
import java.util.Scanner; public class Mode { public static void main (String args []) { Scanner scan = new Scanner(System.in); int MAX_INPUTS = 10000; boolean flag = false; System.out.print ("Input the size of your array: "); int size; // How many nubers will be in the user array do { size = scan.nextInt(); if (size == 1) { System.out.print ("\nError. You must enter a number more than 1.\n\n"); continue; } else if (size > MAX_INPUTS || size < 0) { System.out.print ("\nError. You muste enter a number less than " + MAX_INPUTS + " or greater than 0\n\n"); continue; } else flag = true; // a ligit answer has been entered. } while (flag != true); int array[] = new int[size], values[][] = new int[2][MAX_INPUTS + 1], ticks = 0; System.out.print ("\nNow input the numbers for your array.\n\n"); /* Taking inputs from the user */ while (ticks < size) { System.out.print ("Number " + (ticks + 1) + ": "); array[ticks] = scan.nextInt(); if (array[ticks] > MAX_INPUTS || array[ticks] < 0) { System.out.print ("\nError. Number cannot be greater than " + MAX_INPUTS + " or less than 0\n\n"); continue; } ++ticks; } /* * values[][] array will hold the info for how many times numbers 0 - 10000 appear in array[]. Column 0 will hold numbers from 0 -1000, and column 1 will hold the number of * of repititions the number in column 0 occured in the users inputed array. */ for (int i = 0; i < MAX_INPUTS; ++i) // Initalize Column zero with numbers starting at zeor, and ending and MAX_INPUTS. values[0][i] = i; for (int i = 0; i < size; ++i) // Find the repatitions of the numbers in array[] that correspond to the number in column zere of values[][]. for (int j = 0; j < MAX_INPUTS; ++j) if (array[i] == j) ++values[1][j]; sort (array, size); System.out.print ("\n\nHere are the numbers you entered.\n\n"); // show the values the user entered in ascending order. for (int i = 0; i < size; ++i) { if (i == size - 1) // the last inputed number System.out.print (array[i]); // don't allow an extra comma. else System.out.print (array[i] + ", "); } // Show the user how many times each of the values he/she entered occured. System.out.print ("\n\nThis is the amount of times each of the values you entered occured:\n"); for (int i = 0; i < MAX_INPUTS; ++i) { if (values[1][i] == 1) System.out.print (i + " was entered " + values[1][i] + " time\n"); // avoid: 2 was entered 1 times else if (values[1][i] != 0) System.out.print (i + " was entered " + values[1][i] + " times\n"); // avoid: 2 was entered 2 time } /* -------------------------------------------------------------------- | Finding the Mode/Modes | -------------------------------------------------------------------- */ /* The process begins with creating a second array that is the exactly the same as the values[][] (First for loop). Then I sort the duplicate[] array to find the mode * (highest number in the duplicate[]/values[][] arrays. Int max is then assigned the highest number. Remembering that the values[][] array: column 0 contains numbers ranging * from 1 to 10000, it keeps track of where the numbers in column were originally located, in which you can compare to the duplicate array which is sorted. Then I can set * up a flag that tells you whether there is more than one mode. If so, the printing of these modes will look neater and the grammar can be changed accordingly. */ int duplicate[] = new int [10001], mode[] = new int [size], max, mode_counter = 0; boolean multi_mode = false, all_same; for (int i = 0; i < MAX_INPUTS; ++i) duplicate[i] = values[1][i]; // copy values array. sort (duplicate, MAX_INPUTS); max = duplicate[MAX_INPUTS - 1]; // the last number in the sorted array is the greatest. all_same = test (duplicate, MAX_INPUTS, size, max); // this is the test to see if all the numbers in the user array occured the same amount of times. int c = 0; // a counter /* The mode of the user inputed array will be recorded in the values array. The sort of the duplicate array told me what was the higest number in that array. Now I can * see where that highest number used to be in the original values array and recored the corresponding number in the column zero, which was only filled with numbers 0 - * 10000. Thus telling me the mode/modes. */ for (int i = 0; i < MAX_INPUTS; ++i) { if (values[1][i] == max) { mode[c++] = values[0][i]; ++mode_counter; } } if (mode[1] != 0) //mode[0] (the first cell, has a number stored from the last for loop. If the second cell has a number other than zero, that tells me there is more than 1 mode. multi_mode = true; if (multi_mode == false) System.out.print ("\nThe mode of your array is " + mode[0]); // For correct grammer. else if (all_same == true) System.out.print ("\nAll of the numbers entered appeared the same amount of times. "); // See the boolean function for more details else // If here there is more than one mode. { System.out.print ("\nThe modes of yoru array are "); for (int i = 0; i < mode_counter; ++i) { if (mode_counter > 2 && i == (mode_counter - 1)) // If there is more than two modes and the final mode is to be printed. System.out.print ("& " + mode[i]); else if (mode_counter == 2) { // This is true if there is two modes. The else clause will print the first number, and this will print the amper sign and the second mode. System.out.print (mode[0] + " & " + mode[1]); break; } else System.out.print (mode[i] + ", "); } } } public static void sort (int list[], int max) // Its the bubble sort if you're wondering. { int place, count, temp; for (place = 0; place < max; ++place) for (count = max - 1; count > place; --count) if (list[count - 1] > list[count]) { temp = list[count-1]; list[count - 1] = list[count]; list[count] = temp; } } /* The test to see if there isn't a mode. If the amount of the mode number is the same as the amount of numbers there are in the array is true, or if the size entered by the * user (input) modulo the mode value is equal to zero (say, all the numbers in an array of ten were entered twice: 1, 1, 2, 2, 3, 3, 4, 4, 5, 5). */ public static boolean test (int list[], int limit, int input, int max) { int counter = 0, anti_counter = 0; for (int i = 0; i < limit; ++i) if (list[i] == max) ++counter; // count the potential modes else if (list[i] !=0 && list[i] != max) ++anti_counter; // count every thing else except zeros. if (counter == input || (input % max == 0 && anti_counter == 0) ) return true; else return false; } }
尽管这可能不是最有效的解决方案，但它将打印所有最高模式：
public static int mode(int a[]) { int maxValue=-1, maxCount=0; for (int i = 0; i < a.length; i++) { int count = 0; for (int j = 0; j < a.length; j++) { if (a[j] == a[i]) count++; } } if (count > maxCount) { maxCount = count; maxValue = a[i]; } } //loop again and print only the highest modes for (int i = 0; i < a.length; i++) { int count = 0; for (int j = 0; j < a.length; j++) { if (a[j] == a[i]) count++; } } if (count == maxCount) { System.out.println(a[i]); } } }
希望这可以帮助。 这是我的答案。 希望能帮助到你
public List mode(double[] m) { HashMap freqs = new HashMap(); for (double d : m) { Double freq = freqs.get(d); freqs.put(d, (freq == null ? 1 : freq + 1)); } List mode = new ArrayList (); List frequency = new ArrayList (); List values = new ArrayList (); for (Map.Entry entry : freqs.entrySet()) { frequency.add(entry.getValue()); values.add(entry.getKey()); } double max = Collections.max(frequency); for(int i=0; i< frequency.size();i++) { double val =frequency.get(i); if(max == val ) { mode.add(values.get(i)); } } return mode; }