foo.cc: In function 'int main()':
foo.cc:10:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   10 |  for(int i=0;i<str.size()-1;i++)
      |              ~^~~~~~~~~~~~~
foo.cc:11:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   11 |   for(int j=i+1;j<str.size();j++)
      |                 ~^~~~~~~~~~~
foo.cc:12:34: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   12 |    if(str[i]==str[j]&&str[i]>='a'&&str[i]<='z'||str[i]>='A'&&str[i]<='Z')
foo.cc:15:27: warning: operation on 'k' may be undefined [-Wsequence-point]
   15 |   maxa[++k]=max(a[i],maxa[++k]);
      |                           ^~~
foo.cc:15:27: warning: operation on 'k' may be undefined [-Wsequence-point]

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