/in/foo.cc: In function 'int main()':
/in/foo.cc:22:19: warning: format '%s' expects argument of type 'char*', but argument 2 has type 'char (*)[55]' [-Wformat=]
   scanf("%s",&s[i]);
                   ^
/in/foo.cc:32:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(k=0;k<strlen(s[j]);k++)
            ~^~~~~~~~~~~~~