foo.cc: In member function 'Wint& Wint::check()':
foo.cc:27:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |         for(int i=1; i<size(); ++i)
      |                      ~^~~~~~~
foo.cc: In function 'Wint& operator+=(Wint&, const Wint&)':
foo.cc:91:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   91 |     for(int i=0; i!=b.size(); ++i)a[i]+=b[i];
      |                  ~^~~~~~~~~~
foo.cc: In function 'Wint& operator-=(Wint&, Wint)':
foo.cc:102:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  102 |     for(int i=0; i!=b.size(); a[i]-=b[i],++i)
      |                  ~^~~~~~~~~~
foo.cc: In function 'Wint operator*(const Wint&, const Wint&)':
foo.cc:124:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  124 |     for(int i=0; i!=a.size(); ++i)
      |                  ~^~~~~~~~~~
foo.cc:125:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  125 |         for(int j=0; j!=b.size(); ++j)
      |                      ~^~~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:182:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  182 |     scanf("%d %d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~
foo.cc:187:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  187 |             scanf("%d", &cur);
      |             ~~~~~^~~~~~~~~~~~

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