/in/foo.cc: In function 'int main()':
/in/foo.cc:80:24: warning: iteration 4 invokes undefined behavior [-Waggressive-loop-optimizations]
     tmp[j+1] = (tmp[j+1]^i)&((1<<5)-1);
                 ~~~~~~~^
/in/foo.cc:78:21: note: within this loop
    for (int j = 1;j <= 5;i = tmp[j],j++) {
                   ~~^~~~