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Histogram.java
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59 lines (51 loc) · 1.45 KB
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import java.util.Random;
/**
* Example code related to histograms.
*/
public class Histogram {
/**
* Returns an array of random integers.
*/
public static int[] randomArray(int size) {
Random random = new Random();
int[] a = new int[size];
for (int i = 0; i < a.length; i++) {
a[i] = random.nextInt(100);
}
return a;
}
/**
* Computes the number of array elements in [low, high).
*/
public static int inRange(int[] a, int low, int high) {
int count = 0;
for (int i = 0; i < a.length; i++) {
if (a[i] >= low && a[i] < high) {
count++;
}
}
return count;
}
public static void main(String[] args) {
int numValues = 8;
int[] array = randomArray(numValues);
ArrayExamples.printArray(array);
int[] scores = randomArray(30);
int a = inRange(scores, 90, 100);
int b = inRange(scores, 80, 90);
int c = inRange(scores, 70, 80);
int d = inRange(scores, 60, 70);
int f = inRange(scores, 0, 60);
// making a histogram
int[] counts = new int[100];
for (int i = 0; i < scores.length; i++) {
int index = scores[i];
counts[index]++;
}
// histogram with enhanced for loop
counts = new int[100];
for (int score : scores) {
counts[score]++;
}
}
}