foo.cc: In function 'int main()':
foo.cc:13:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (;i < sentence.length();++i)
           ~~^~~~~~~~~~~~~~~~~~~
foo.cc:15:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (j = 0;j < word.length();++j)
                    ~~^~~~~~~~~~~~~~~
foo.cc:20:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (j == word.length() &&( i+j == sentence.length()||sentence[i + j] == ' ' ) )
             ~~^~~~~~~~~~~~~~~~
foo.cc:20:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (j == word.length() &&( i+j == sentence.length()||sentence[i + j] == ' ' ) )
                                    ~~~~^~~~~~~~~~~~~~~~~~~~

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