Task3.java

import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

class BankStatementBatchProcessor {

    // FIX: AtomicInteger makes increments thread-safe; int++ is a non-atomic read-modify-write operation.
    private final AtomicInteger processedCount = new AtomicInteger(0);

    public void process(List<StatementRecord> records) throws InterruptedException {
        ExecutorService executor = Executors.newFixedThreadPool(10);

        for (StatementRecord record : records) {
            executor.submit(() -> {
                processRecord(record);
                // FIX: Use atomic increment so concurrent worker threads cannot overwrite each other's updates.
                processedCount.incrementAndGet();
            });
        }
        executor.shutdown();
        executor.awaitTermination(5, TimeUnit.MINUTES);
    }

    public int getProcessedCount() {
        // FIX: Read the current atomic value instead of returning a shared mutable int directly.
        return processedCount.get();
    }

    private void processRecord(StatementRecord record) {
        // Existing processing logic remains unchanged.
    }
}