题解（关注一下我吧，必回关）

#include<iostream>
using namespace std;
int main(){
int a,c=0,m;
cin>>a;
m=a-2;
for(int i=1;i<=(a-1)/2;i++){
for(int t=1;t<=c;t++){
cout<<"-";
}
cout<<"+";
for(int u=1;u<=m;u++){
cout<<"-";
}
cout<<"+";
for(int t=1;t<=c;t++){
cout<<"-";
}
cout<<endl;
m-=2;
c++;
}
for(int h=1;h<=c;h++){
cout<<"-";
}
cout<<"+";
for(int h=1;h<=c;h++){
cout<<"-";
}
cout<<endl;
c--;
m+=2;
for(int i=1;i<=(a-1)/2;i++){
for(int t=1;t<=c;t++){
cout<<"-";
}
cout<<"+";
for(int u=1;u<=m;u++){
cout<<"-";
}
cout<<"+";
for(int t=1;t<=c;t++){
cout<<"-";
}
cout<<endl;
m+=2;
c--;
}
return 0;
}