View Compilation Error

0_0_33543626_142.cpp:64:2: error: invalid preprocessing directive #re
 #re register
  ^
0_0_33543626_142.cpp: In function 'void dfs(int, int)':
0_0_33543626_142.cpp:92:9: error: 're' was not declared in this scope
     for(re int i=head[n];i;i=s[i].last) {
         ^
0_0_33543626_142.cpp:92:26: error: 'i' was not declared in this scope
     for(re int i=head[n];i;i=s[i].last) {
                          ^
0_0_33543626_142.cpp:95:14: error: 'val' was not declared in this scope
         dis+=val;
              ^
0_0_33543626_142.cpp: In function 'int main()':
0_0_33543626_142.cpp:112:13: error: 're' was not declared in this scope
         for(re int i=1;i<a;i++) {
             ^
0_0_33543626_142.cpp:112:24: error: 'i' was not declared in this scope
         for(re int i=1;i<a;i++) {
                        ^