代码：

#include <iostream>
#include <cstring>
using namespace std;
//TODO
//TODO
//TODO
int main(void)
{
	
	char s;
	cin>>s;
	cout<<strupr(s)<<endl;
	
	return 0;
}

ERROR：

/tmp/compiler_398nc81h/src: 在函数‘int main()’中:
/tmp/compiler_398nc81h/src:12:8: 错误：‘strupr’ was not declared in this scope; did you mean ‘strstr’?
   12 |  cout<<strupr(s)<<endl;
      |        ^~~~~~
      |        strstr