请更新您的includePath

我正在上一门使用C ++的学校课程。有了他们给我们的代码，我们在标题中添加了以下内容：

#include <cstdlib>
#include <cmath>
#include <iostream>
#include "cs221util/PNG.h"
#include "cs221util/HSLAPixel.h"

我得到错误

{
    "resource": "/home/k/xxx/cs221/lab_debug/sketchify.cpp",
    "owner": "C/C++",
    "code": "1696",
    "severity": 8,
    "message": "#include errors detected. Please update your includePath. Squiggles are disabled for this translation unit (/home/k/xxx/cs221/lab_debug/sketchify.cpp).",
    "source": "C/C++",
    "startLineNumber": 4,
    "startColumn": 1,
    "endLineNumber": 4,
    "endColumn": 27
}

和

{
    "resource": "/home/k/xxx/cs221/lab_debug/sketchify.cpp",
    "owner": "C/C++",
    "code": "1696",
    "severity": 8,
    "message": "cannot open source file \"iostream\"",
    "source": "C/C++",
    "startLineNumber": 3,
    "startColumn": 1,
    "endLineNumber": 3,
    "endColumn": 20
}

即使所有内容都能编译并运行良好。我在网上寻找，也许解决方案正在修改c_cpp_properties.json？我打开它，不知道该文件中的任何含义。我应该做些什么？什么意思