GC 与日志：先读出分配和停顿，再调整参数

import java.util.*;

public class Main {
    record Candidates(List<Integer> objects,long bytes) {}
    static Candidates mark(long[] sizes,int[][] edges,int[] roots) {
        Objects.requireNonNull(sizes); Objects.requireNonNull(edges); Objects.requireNonNull(roots);
        int n=sizes.length; List<List<Integer>> graph=new ArrayList<>();
        for(long size:sizes) { if(size<0) throw new IllegalArgumentException("size"); graph.add(new ArrayList<>()); }
        for(int[] edge:edges) {
            if(edge==null || edge.length!=2 || edge[0]<0 || edge[0]>=n || edge[1]<0 || edge[1]>=n)
                throw new IllegalArgumentException("edge");
            graph.get(edge[0]).add(edge[1]);
        }
        boolean[] live=new boolean[n]; ArrayDeque<Integer> queue=new ArrayDeque<>();
        for(int root:roots) {
            if(root<0 || root>=n) throw new IllegalArgumentException("root");
            if(!live[root]) { live[root]=true; queue.add(root); } // 入队即标记，重复根不重复安排。
        }
        while(!queue.isEmpty()) {
            int node=queue.remove();
            for(int target:graph.get(node)) if(!live[target]) {
                live[target]=true; queue.add(target); // 环与共享引用通过标记去重。
            }
        }
        List<Integer> dead=new ArrayList<>(); long bytes=0;
        for(int i=0;i<n;i++) if(!live[i]) {
            dead.add(i); bytes=Math.addExact(bytes,sizes[i]); // 候选字节溢出时显式失败。
        }
        return new Candidates(List.copyOf(dead),bytes);
    }
    static void check(boolean ok) { if(!ok) throw new AssertionError(); }
    public static void main(String[] args) {
        int[][] graph={{0,1},{1,0},{2,3},{3,2}};
        check(mark(new long[]{10,20,30,40},graph,new int[]{0}).equals(new Candidates(List.of(2,3),70)));
        check(mark(new long[]{1,2},new int[][]{{0,1},{1,0}},new int[0]).bytes()==3);
        check(mark(new long[]{1,2},new int[][]{{0,1}},new int[]{0,0}).objects().isEmpty());
        check(mark(new long[0],new int[0][],new int[0]).bytes()==0);
        check(mark(new long[]{0},new int[0][],new int[0]).objects().equals(List.of(0)));
        try { mark(new long[]{Long.MAX_VALUE,1},new int[0][],new int[0]); throw new AssertionError(); }
        catch(ArithmeticException expected) { }
        try { mark(new long[]{1},new int[0][],new int[]{1}); throw new AssertionError(); }
        catch(IllegalArgumentException expected) { }
        System.out.println("PASS 7");
    }
}