Matriz de impresión alternativa de subprocesos múltiples (implementación de C ++ 11)

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

using namespace std;

mutex mtx;
condition_variable cond;
int counter = 0;
int order = 0;

// k -> 交替打印数组个数
// o -> 数组打印的次序 
template<typename T>
void print(vector<T>& nums, int k, int o) {
    
    
    int i = 0;
    for (T num: nums) {
    
    
        {
    
    
            unique_lock<mutex> locker(mtx);
            while (order%k!=o || k*i > counter) {
    
    
                cond.wait(locker);
            }
            cout << num;
            counter++;
            order++;
        }
        i++;
        cond.notify_all(); // 必须唤醒所有阻塞的线程
    }
}

// 输出：123a456b789c101112d
int main () {
    
    
    vector<int> v1{
    
    1,4,7,10};
    vector<int> v2{
    
    2,5,8,11};
    vector<int> v3{
    
    3,6,9,12};
    vector<char> v4{
    
    'a','b','c','d'};
    thread t1(print<int>, ref(v1), 4, 0);
    thread t2(print<int>, ref(v2), 4, 1);
    thread t3(print<int>, ref(v3), 4, 2);
    thread t4(print<char>, ref(v4), 4, 3);
    t1.join();
    t2.join();
    t3.join();
    t4.join();
}