为什么输出没问题，要求达不到
package zh.codegym.task.task18.task1803;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashMap;
/*
数量最大的字节
*/
public class Solution {
public static void main(String[] args) throws Exception {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
String filename = reader.readLine();
FileInputStream inputStream = new FileInputStream(filename);
ArrayList<Integer> list = new ArrayList<>();
HashMap<Integer, Integer> map = new HashMap<>();
long sum = 0;
long max = 0;
int a = 0;
while (inputStream.available() > 0) {
int data = inputStream.read();
list.add(data);
}
inputStream.close();
for (int i = 0; i < list.size(); i++) {
if (max < sum) {
a = i;
max = sum;
sum = 0;
} else {
sum = 0;
}
for (int j = 0; j < list.size(); j++) {
if (list.get(j).equals(list.get(i))) {
sum++;
map.put(list.get(j), Math.toIntExact(sum));
}
}
}
int b = list.get(a) - '0';
System.out.println(b+" ");
}
}