foo.c: In function 'SetUnion':
foo.c:32:28: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   32 |                         if(a2[i]=a1[j])
      |                            ^~
foo.c:38:19: warning: 'judge' may be used uninitialized [-Wmaybe-uninitialized]
   38 |                 if(judge==1)
      |                   ^
foo.c:26:13: note: 'judge' was declared here
   26 |         int judge;
      |             ^~~~~

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