foo.cpp: In function 'int main()':
foo.cpp:88:19: error: name lookup of 'i' changed for ISO 'for' scoping [-fpermissive]
         for(int r=i+1;r<=n;r++)
                   ^
foo.cpp:88:19: note: (if you use '-fpermissive' G++ will accept your code)
foo.cpp:89:21: error: 'j' was not declared in this scope
             solve(i,j);
                     ^