foo.cc: In function 'int main()':
foo.cc:39:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |         for (int j=0;j<a[i].size();j++) {
      |                      ~^~~~~~~~~~~~
foo.cc:29:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   29 |     scanf("%d%d%d",&n,&s,&e);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~
foo.cc:31:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   31 |         scanf("%d%d%d",&b[i].l,&b[i].r,&b[i].v);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务