foo.cc: In function 'int main()':
foo.cc:12:9: error: 'i' was not declared in this scope
   12 |     for(i=0;i<=n;i++)
      |         ^
foo.cc:15:19: warning: self-comparison always evaluates to true [-Wtautological-compare]
   15 |            if(a[j]==a[j]^a[i])
      |               ~~~~^~~~~~
foo.cc:27:8: error: 'i' was not declared in this scope
   27 |    for(i=0;i<=n;i++)
      |        ^

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