foo.cc: In function 'void solve()':
foo.cc:37:17: error: redeclaration of 'int a'
             int a = p[i].x - r,b = p[i].y + l,c = p[j].x - r,d = p[j].y + l;
                 ^
foo.cc:35:17: note: 'int a' previously declared here
             int a = p[i].x + r,b = p[i].y - l,c = p[j].x + r,d = p[j].y - l;
                 ^
foo.cc:37:32: error: redeclaration of 'int b'
             int a = p[i].x - r,b = p[i].y + l,c = p[j].x - r,d = p[j].y + l;
                                ^
foo.cc:35:32: note: 'int b' previously declared here
             int a = p[i].x + r,b = p[i].y - l,c = p[j].x + r,d = p[j].y - l;
                                ^
foo.cc:37:47: error: redeclaration of 'int c'
             int a = p[i].x - r,b = p[i].y + l,c = p[j].x - r,d = p[j].y + l;
                                               ^
foo.cc:35:47: note: 'int c' previously declared here
             int a = p[i].x + r,b = p[i].y - l,c = p[j].x + r,d = p[j].y - l;
                                               ^
foo.cc:37:62: error: redeclaration of 'int d'
             int a = p[i].x - r,b = p[i].y + l,c = p[j].x - r,d = p[j].y + l;
                                                              ^
foo.cc:35:62: note: 'int d' previously declared here
             int a = p[i].x + r,b = p[i].y - l,c = p[j].x + r,d = p[j].y - l;
                                                              ^