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import java.util.HashMap; public class Main { public static void main(String[] args) { String text = "banana"; HashMap<Character, Integer> freq = new HashMap<>(); for (char c : text.toCharArray()) { freq.put(c, freq.getOrDefault(c, 0) + 1); } System.out.println(freq); } }
{a=3, b=1, n=2}
编辑器