C++修改指向结构的指针向量会导致未定义的行为

我有一个指针向量，指向存储在我学校项目的另一个向量中的结构。当我试图使用指针更改结构中的元素时，由于某种原因，它导致了未定义的行为。我撕掉了与下面的问题相关的部分代码。

#include <vector>
#include <string>
#include <iostream>
class someException{};
enum class ProcessStatus{
RUNNING,
READY
};
struct Process{
int priority;
std::string PID;
ProcessStatus status;
Process(){
status = ProcessStatus::READY;
}
};
struct ReadyList{
std::vector<Process*> priority1;
std::vector<Process*> priority0;
};
class ProcessManager{
private:
std::vector<Process> processList;
ReadyList readyList;
public:
ProcessManager(){};
void createProcess(std::string PID, int priority){
Process process;
process.priority = priority;
process.PID = PID;
if (priority == 0)
process.status = ProcessStatus::RUNNING;
processList.push_back(process);
switch(priority){
case 0:
readyList.priority0.push_back(&processList.at(processList.size()-1));
break;
case 1:
readyList.priority1.push_back(&processList.at(processList.size()-1));
break;
default:
throw someException();
}
schedule(findRunningProcess());
}
void printProcesses(){
std::cout<<"ReadyList results:"<<std::endl;
for(auto &process: readyList.priority0){
std::cout << "Process: "<< process->PID << " , Priority: "<<process->priority;
if (process->status == ProcessStatus::RUNNING)
std::cout << ", Status: RUNNING"<< std::endl;
else
std::cout <<", Status: READY"<<std::endl;
}
for(auto &process: readyList.priority1){
std::cout << "Process: "<< process->PID << " , Priority: "<<process->priority;
if (process->status == ProcessStatus::RUNNING)
std::cout << ", Status: RUNNING"<< std::endl;
else
std::cout <<", Status: READY"<<std::endl;
}
std::cout<<"ProcessList results: "<<std::endl;
for(auto &process: processList){
std::cout << "Process: "<< process.PID << " , Priority: "<<process.priority;
if (process.status == ProcessStatus::RUNNING)
std::cout << ", Status: RUNNING"<< std::endl;
else
std::cout <<", Status: READY"<<std::endl;
}
}
private:
void schedule(Process* currentProcess){
Process* highestPriorityProcess;
if (readyList.priority1.size()>0)
highestPriorityProcess = readyList.priority1[0];
else
highestPriorityProcess = readyList.priority0[0];
if (currentProcess->priority < highestPriorityProcess->priority){
currentProcess->status = ProcessStatus::READY;
highestPriorityProcess->status = ProcessStatus::RUNNING;
}
}
Process* findRunningProcess(){
for (auto &process: processList){
if (process.status == ProcessStatus::RUNNING){
return &process;
}
}
return nullptr;
}
};
int main(){
ProcessManager pm = ProcessManager();
pm.createProcess("ROOT", 0);
std::cout<<"After creating process ROOT"<<std::endl;
pm.printProcesses();
pm.createProcess("A", 1);
std::cout<<"After creating process A"<<std::endl;
pm.printProcesses();
return 0;
};

输出结果是：

After creating process ROOT
ReadyList results:
Process: ROOT , Priority: 0, Status: RUNNING
ProcessList results: 
Process: ROOT , Priority: 0, Status: RUNNING
After creating process A
ReadyList results:
Process: ROOT , Priority: 0, Status: RUNNING
Process: A , Priority: 1, Status: RUNNING
ProcessList results: 
Process: ROOT , Priority: 0, Status: READY
Process: A , Priority: 1, Status: RUNNING

ProcessList设置为正确的值，进程A正在运行，进程ROOT处于就绪状态，但由于某些原因ReadyList未更改。在我的原始代码中，readylist中进程ROOT的PID字符串值变为空，并且存储在进程中的映射值(我在本例中忽略了它)也在更改状态后被删除。我还测试了直接使用readyList指针进行更改，而不是使用findRunningProcess函数返回的指针，这并没有解决PID和映射值的问题，而是在进程状态中导致了一些其他未定义的行为。我不知道是什么原因造成的，请帮忙！非常感谢。