View Compilation Error

0_0_36726175_5456.cpp: In function 'void push_up(int)':
0_0_36726175_5456.cpp:22:44: error: 'r' was not declared in this scope
     sum[rt] = sum[ls[rt]] + sum[rs[rt]] + (r - l + 1) * add[rt];
                                            ^
0_0_36726175_5456.cpp:22:48: error: 'l' was not declared in this scope
     sum[rt] = sum[ls[rt]] + sum[rs[rt]] + (r - l + 1) * add[rt];
                                                ^