foo.cc: In function 'std::vector<int> mul(std::vector<int>&, int)':
foo.cc:9:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    9 |  for(int i=0;i<a.size()||t;i++){
      |              ~^~~~~~~~~
foo.cc:10:7: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   10 |   if(i<a.size()) t+=a[i]*b;
      |      ~^~~~~~~~~
foo.cc: In function 'std::vector<int> add(std::vector<int>&, std::vector<int>&)':
foo.cc:21:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |  while(i<a.size()||j<b.size()){
      |        ~^~~~~~~~~
foo.cc:21:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |  while(i<a.size()||j<b.size()){
      |                    ~^~~~~~~~~
foo.cc:23:7: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |   if(i<a.size()) tmp+=a[i++];
      |      ~^~~~~~~~~
foo.cc:24:7: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   24 |   if(j<b.size()) tmp+=b[j++];
      |      ~^~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:33:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   33 |  scanf("%d %d",&n,&m);
      |  ~~~~~^~~~~~~~~~~~~~~
foo.cc:37:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   37 |    scanf("%d",&a[i][j]);
      |    ~~~~~^~~~~~~~~~~~~~~

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