经典的PCA人脸识别算法，C++源代码都是我自己写的，第一次上传，写得不好的地方请多多指教。已经经过我的多次测试和观察数据，代码运行正常，下载之后只要配置好opencv即可。 -The classic PCA face recognition algorithm, C++ source code I wrote it myself, the first upload, poorly written exhibitions. I have passed many tests and observa