当循环变得更大时，为什么这个带有vector.insert()的并行C++循环会崩溃？

#include <iostream>
#include <vector>
#include <thread>
#include <mutex>

std::vector<int> sharedVector;
std::mutex mtx;

void insertElements(int start, int end) {
    for (int i = start; i <= end; ++i) {
        std::lock_guard<std::mutex> lock(mtx);
        sharedVector.insert(sharedVector.end(), i);
    }
}

int main() {
    const int numThreads = 4;
    const int totalElements = 100000;
    std::vector<std::thread> threads;

    int chunkSize = totalElements / numThreads;
    for (int i = 0; i < numThreads; ++i) {
        int start = i * chunkSize;
        int end = (i == numThreads - 1) ? totalElements : start + chunkSize - 1;
        threads.emplace_back(insertElements, start, end);
    }

    for (auto& t : threads) {
        t.join();
    }

    std::cout << "Total elements: " << sharedVector.size() << std::endl;
    return 0;
}