C++求最长单词最短单词，openjudge头文件报错

#include
#include
#include
using namespace std;
int main()
{
char s[20001];
int maxlen=0,minlen=101,maxst,minst,slen;
int i=0,j=0;
gets(s);
slen=strlen(s);
cout<<slen<<endl;
while(1){
while(i<slen && (s[i]==' '|| s[i]==',')) i++;
if(i>=slen) break;
j=i;
while(j<slen && s[j]!=' '&& s[j]!=',') j++;
cout<<"单词的长度为"<<j-i<<endl; //取出的单词长度为j-i;
if((j-i)>maxlen)
{
maxlen=j-i;maxst=i;}

   if((j-i)<minlen)   
   { minlen=j-i;
   minst=i;}
   i=j;

}

for(i=maxst;i<=maxst+maxlen-1;i++) cout<<s[i]; //输出最长的单词；
cout<<endl;
for(i=minst;i<=minst+minlen-1;i++) cout<<s[i]; //输出最短的单词；
cout<<endl;
}
头文件如下

img

/出现如下报错
/home/runner/temp/30557620.7362/Main.c:1:9: fatal error: iostream: No such file or directory
1 | #include
| ^~~~~~~~~~
compilation terminated./

文件名后缀是.cpp吗