运行 ID: 68432

Main.cc: In function ‘int a(int)’:
Main.cc:5:5: error: expected ‘,’ or ‘;’ before ‘for’
     for(int j=1;j<=i;j++){
     ^~~
Main.cc:5:17: error: ‘j’ was not declared in this scope
     for(int j=1;j<=i;j++){
                 ^