23 lines
675 B
Java
23 lines
675 B
Java
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//: containers/Statistics.java
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// <20>2015 MindView LLC: see Copyright.txt
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// Simple demonstration of HashMap.
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import java.util.*;
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public class Statistics {
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public static void main(String[] args) {
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Random rand = new Random(47);
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Map<Integer,Integer> m = new HashMap<>();
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for(int i = 0; i < 10000; i++) {
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// Produce a number between 0 and 20:
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int r = rand.nextInt(20);
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Integer freq = m.get(r);
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m.put(r, freq == null ? 1 : freq + 1);
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}
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System.out.println(m);
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}
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} /* Output:
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{0=481, 1=502, 2=489, 3=508, 4=481, 5=503, 6=519, 7=471,
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8=468, 9=549, 10=513, 11=531, 12=521, 13=506, 14=477,
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15=497, 16=533, 17=509, 18=478, 19=464}
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*///:~
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