foo.cc: In function 'int main()':
foo.cc:39:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         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]
     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]
         scanf("%d%d%d",&b[i].l,&b[i].r,&b[i].v);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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