/in/foo.cc: In function 'void del(int, int, int, int)':
/in/foo.cc:14:5: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
     if(!rt) return ;tr[rt]--;
     ^~
/in/foo.cc:14:21: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'if'
     if(!rt) return ;tr[rt]--;
                     ^~
/in/foo.cc: In function 'void update(int&, int, int, int)':
/in/foo.cc:21:5: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
     if(!rt)  rt=++cnt;tr[rt]++;
     ^~
/in/foo.cc:21:23: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'if'
     if(!rt)  rt=++cnt;tr[rt]++;
                       ^~
/in/foo.cc: In function 'int read()':
/in/foo.cc:38:5: warning: this 'while' clause does not guard... [-Wmisleading-indentation]
     while(('0'<=c&&c<='9')) x=x*10+c-48,c=getchar();return x;
     ^~~~~
/in/foo.cc:38:53: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'while'
     while(('0'<=c&&c<='9')) x=x*10+c-48,c=getchar();return x;
                                                     ^~~~~~
/in/foo.cc: At global scope:
/in/foo.cc:41:7: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main () {
       ^